Model Extended KIM ID = 
=== Verification check vc-periodicity-support start (2022-11-29 18:16:05) ===
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!!!!!  VERIFICATION CHECK: vc-periodicity-support  !!!!!
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Description: Check that the model supports periodic boundary conditions
             correctly. If the simulation box is increased by an integer factor
             along a periodic direction, the total energy must multiply by that
             factor and the forces on atoms that are periodic copies of each
             other must be the same. The check is performed for a randomly
             distorted non-periodic face-centered cubic (FCC) cube base
             structure. Separate configurations are tested for each species
             supported by the model, as well as one containing a random
             distribution of all species. For each configuration, all possible
             combinations of periodic boundary conditions are tested: TFF, FTF,
             FFT, TTF, TFT, TTF, TTT (where 'T' indicates periodicity along a
             direction, and 'F' indicates no periodicity). The verification
             check passes if the energy of all configurations that the model is
             able to compute support all periodic boundary conditions correctly.
             Configurations used for testing are provided as auxiliary files.

Author: Ellad Tadmor

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Results for KIM Model      : EAM_Dynamo_DeluigiPasianotValencia_2021_FeNiCrCoCu__MO_657255834688_000
Supported species          : Co Cr Cu Fe Ni

random seed                = 13
lattice constant (orig)    = 3.000
perturbation amplitude     = 0.300
number unit cells per side = 1
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MONOATOMIC STRUCTURE -- Species = Co, PBC = TTT   (Configuration in file "config-Co-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -8.407360144404631
2^p V(r_1,...,r_N)    = -8.407360144404016

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
  1   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
  2   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
  3    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
  4    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
  5   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
  6   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
  7    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
  8    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
  9   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 10   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 11    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
 12    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
 13   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 14   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 15    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
 16    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
 17   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 18   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 19    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
 20    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
 21   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 22   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 23    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
 24    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
 25   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 26   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 27    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
 28    6.60084069e+00   -1.02583086e+01    3.26775115e+00   |   6.60084069e+00   -1.02583086e+01    3.26775115e+00   
 29   -7.98895922e+00    8.48984007e+00    2.24289625e+00   |  -7.98895922e+00    8.48984007e+00    2.24289625e+00   
 30   -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   |  -4.09043140e+00   -8.58183164e+00   -3.73238083e+00   
 31    5.47854993e+00    1.03503001e+01   -1.77826657e+00   |   5.47854993e+00    1.03503001e+01   -1.77826657e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
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MONOATOMIC STRUCTURE -- Species = Co, PBC = TTF   (Configuration in file "config-Co-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 5.563120613152598
2^p V(r_1,...,r_N)    = 5.563120613152612

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    1.05439471e+01    1.20889071e+01   -1.18537372e+01   |   1.05439471e+01    1.20889071e+01   -1.18537372e+01   
  1   -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   |  -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   
  2   -7.72808353e+00   -2.20439980e+00    1.04420501e+01   |  -7.72808353e+00   -2.20439980e+00    1.04420501e+01   
  3    7.12141298e+00   -2.21687570e+00    1.31393124e+01   |   7.12141298e+00   -2.21687570e+00    1.31393124e+01   
  4    1.05439471e+01    1.20889071e+01   -1.18537372e+01   |   1.05439471e+01    1.20889071e+01   -1.18537372e+01   
  5   -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   |  -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   
  6   -7.72808353e+00   -2.20439980e+00    1.04420501e+01   |  -7.72808353e+00   -2.20439980e+00    1.04420501e+01   
  7    7.12141298e+00   -2.21687570e+00    1.31393124e+01   |   7.12141298e+00   -2.21687570e+00    1.31393124e+01   
  8    1.05439471e+01    1.20889071e+01   -1.18537372e+01   |   1.05439471e+01    1.20889071e+01   -1.18537372e+01   
  9   -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   |  -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   
 10   -7.72808353e+00   -2.20439980e+00    1.04420501e+01   |  -7.72808353e+00   -2.20439980e+00    1.04420501e+01   
 11    7.12141298e+00   -2.21687570e+00    1.31393124e+01   |   7.12141298e+00   -2.21687570e+00    1.31393124e+01   
 12    1.05439471e+01    1.20889071e+01   -1.18537372e+01   |   1.05439471e+01    1.20889071e+01   -1.18537372e+01   
 13   -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   |  -9.93727658e+00   -7.66763160e+00   -1.17276253e+01   
 14   -7.72808353e+00   -2.20439980e+00    1.04420501e+01   |  -7.72808353e+00   -2.20439980e+00    1.04420501e+01   
 15    7.12141298e+00   -2.21687570e+00    1.31393124e+01   |   7.12141298e+00   -2.21687570e+00    1.31393124e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Co, PBC = TFT   (Configuration in file "config-Co-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 8.496882566425672
2^p V(r_1,...,r_N)    = 8.49688256642561

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    5.50865873e+00   -1.38696416e+01   -6.92899158e+00   |   5.50865873e+00   -1.38696416e+01   -6.92899158e+00   
  1   -8.55446792e+00    1.34964720e+01   -3.80549938e+00   |  -8.55446792e+00    1.34964720e+01   -3.80549938e+00   
  2   -5.73507449e+00   -1.45761197e+01    5.28946434e+00   |  -5.73507449e+00   -1.45761197e+01    5.28946434e+00   
  3    8.78088368e+00    1.49492893e+01    5.44502662e+00   |   8.78088368e+00    1.49492893e+01    5.44502662e+00   
  4    5.50865873e+00   -1.38696416e+01   -6.92899158e+00   |   5.50865873e+00   -1.38696416e+01   -6.92899158e+00   
  5   -8.55446792e+00    1.34964720e+01   -3.80549938e+00   |  -8.55446792e+00    1.34964720e+01   -3.80549938e+00   
  6   -5.73507449e+00   -1.45761197e+01    5.28946434e+00   |  -5.73507449e+00   -1.45761197e+01    5.28946434e+00   
  7    8.78088368e+00    1.49492893e+01    5.44502662e+00   |   8.78088368e+00    1.49492893e+01    5.44502662e+00   
  8    5.50865873e+00   -1.38696416e+01   -6.92899158e+00   |   5.50865873e+00   -1.38696416e+01   -6.92899158e+00   
  9   -8.55446792e+00    1.34964720e+01   -3.80549938e+00   |  -8.55446792e+00    1.34964720e+01   -3.80549938e+00   
 10   -5.73507449e+00   -1.45761197e+01    5.28946434e+00   |  -5.73507449e+00   -1.45761197e+01    5.28946434e+00   
 11    8.78088368e+00    1.49492893e+01    5.44502662e+00   |   8.78088368e+00    1.49492893e+01    5.44502662e+00   
 12    5.50865873e+00   -1.38696416e+01   -6.92899158e+00   |   5.50865873e+00   -1.38696416e+01   -6.92899158e+00   
 13   -8.55446792e+00    1.34964720e+01   -3.80549938e+00   |  -8.55446792e+00    1.34964720e+01   -3.80549938e+00   
 14   -5.73507449e+00   -1.45761197e+01    5.28946434e+00   |  -5.73507449e+00   -1.45761197e+01    5.28946434e+00   
 15    8.78088368e+00    1.49492893e+01    5.44502662e+00   |   8.78088368e+00    1.49492893e+01    5.44502662e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Co, PBC = TFF   (Configuration in file "config-Co-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 3.7151714466324544
2^p V(r_1,...,r_N)    = 3.715171446632453

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    4.60420495e+00   -1.01651384e+01   -8.97232918e+00   |   4.60420495e+00   -1.01651384e+01   -8.97232918e+00   
  1   -2.85943828e+00    9.88300718e+00   -1.05951857e+01   |  -2.85943828e+00    9.88300718e+00   -1.05951857e+01   
  2   -3.74071782e+00   -1.02043718e+01    1.02617424e+01   |  -3.74071782e+00   -1.02043718e+01    1.02617424e+01   
  3    1.99595115e+00    1.04865031e+01    9.30577246e+00   |   1.99595115e+00    1.04865031e+01    9.30577246e+00   
  4    4.60420495e+00   -1.01651384e+01   -8.97232918e+00   |   4.60420495e+00   -1.01651384e+01   -8.97232918e+00   
  5   -2.85943828e+00    9.88300718e+00   -1.05951857e+01   |  -2.85943828e+00    9.88300718e+00   -1.05951857e+01   
  6   -3.74071782e+00   -1.02043718e+01    1.02617424e+01   |  -3.74071782e+00   -1.02043718e+01    1.02617424e+01   
  7    1.99595115e+00    1.04865031e+01    9.30577246e+00   |   1.99595115e+00    1.04865031e+01    9.30577246e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Co, PBC = FTT   (Configuration in file "config-Co-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 6.683772617409324
2^p V(r_1,...,r_N)    = 6.68377261740934

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.09621500e+01    4.41611450e-01   -2.89652785e+00   |  -1.09621500e+01    4.41611450e-01   -2.89652785e+00   
  1    9.51902689e+00   -9.78481586e+00    7.14793615e+00   |   9.51902689e+00   -9.78481586e+00    7.14793615e+00   
  2    1.33399432e+01    1.11663851e+01   -8.46547632e+00   |   1.33399432e+01    1.11663851e+01   -8.46547632e+00   
  3   -1.18968201e+01   -1.82318074e+00    4.21406802e+00   |  -1.18968201e+01   -1.82318074e+00    4.21406802e+00   
  4   -1.09621500e+01    4.41611450e-01   -2.89652785e+00   |  -1.09621500e+01    4.41611450e-01   -2.89652785e+00   
  5    9.51902689e+00   -9.78481586e+00    7.14793615e+00   |   9.51902689e+00   -9.78481586e+00    7.14793615e+00   
  6    1.33399432e+01    1.11663851e+01   -8.46547632e+00   |   1.33399432e+01    1.11663851e+01   -8.46547632e+00   
  7   -1.18968201e+01   -1.82318074e+00    4.21406802e+00   |  -1.18968201e+01   -1.82318074e+00    4.21406802e+00   
  8   -1.09621500e+01    4.41611450e-01   -2.89652785e+00   |  -1.09621500e+01    4.41611450e-01   -2.89652785e+00   
  9    9.51902689e+00   -9.78481586e+00    7.14793615e+00   |   9.51902689e+00   -9.78481586e+00    7.14793615e+00   
 10    1.33399432e+01    1.11663851e+01   -8.46547632e+00   |   1.33399432e+01    1.11663851e+01   -8.46547632e+00   
 11   -1.18968201e+01   -1.82318074e+00    4.21406802e+00   |  -1.18968201e+01   -1.82318074e+00    4.21406802e+00   
 12   -1.09621500e+01    4.41611450e-01   -2.89652785e+00   |  -1.09621500e+01    4.41611450e-01   -2.89652785e+00   
 13    9.51902689e+00   -9.78481586e+00    7.14793615e+00   |   9.51902689e+00   -9.78481586e+00    7.14793615e+00   
 14    1.33399432e+01    1.11663851e+01   -8.46547632e+00   |   1.33399432e+01    1.11663851e+01   -8.46547632e+00   
 15   -1.18968201e+01   -1.82318074e+00    4.21406802e+00   |  -1.18968201e+01   -1.82318074e+00    4.21406802e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Co, PBC = FTF   (Configuration in file "config-Co-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 12.221675145421658
2^p V(r_1,...,r_N)    = 12.221675145421655

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.43869276e+01   -3.54490672e+00   -1.32056675e+01   |  -1.43869276e+01   -3.54490672e+00   -1.32056675e+01   
  1    1.12742263e+01    7.47849641e+00   -1.52909968e+01   |   1.12742263e+01    7.47849641e+00   -1.52909968e+01   
  2    1.44748271e+01   -8.44881732e+00    1.65747810e+01   |   1.44748271e+01   -8.44881732e+00    1.65747810e+01   
  3   -1.13621257e+01    4.51522763e+00    1.19218833e+01   |  -1.13621257e+01    4.51522763e+00    1.19218833e+01   
  4   -1.43869276e+01   -3.54490672e+00   -1.32056675e+01   |  -1.43869276e+01   -3.54490672e+00   -1.32056675e+01   
  5    1.12742263e+01    7.47849641e+00   -1.52909968e+01   |   1.12742263e+01    7.47849641e+00   -1.52909968e+01   
  6    1.44748271e+01   -8.44881732e+00    1.65747810e+01   |   1.44748271e+01   -8.44881732e+00    1.65747810e+01   
  7   -1.13621257e+01    4.51522763e+00    1.19218833e+01   |  -1.13621257e+01    4.51522763e+00    1.19218833e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Co, PBC = FFT   (Configuration in file "config-Co-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -3.788634352569095
2^p V(r_1,...,r_N)    = -3.7886343525691015

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -9.23751522e+00   -7.69637647e+00    2.48814717e+00   |  -9.23751522e+00   -7.69637647e+00    2.48814717e+00   
  1    9.39480501e+00    7.90027093e+00   -2.02031421e+00   |   9.39480501e+00    7.90027093e+00   -2.02031421e+00   
  2    7.92538896e+00   -7.75734393e+00    1.50944682e+00   |   7.92538896e+00   -7.75734393e+00    1.50944682e+00   
  3   -8.08267874e+00    7.55344947e+00   -1.97727978e+00   |  -8.08267874e+00    7.55344947e+00   -1.97727978e+00   
  4   -9.23751522e+00   -7.69637647e+00    2.48814717e+00   |  -9.23751522e+00   -7.69637647e+00    2.48814717e+00   
  5    9.39480501e+00    7.90027093e+00   -2.02031421e+00   |   9.39480501e+00    7.90027093e+00   -2.02031421e+00   
  6    7.92538896e+00   -7.75734393e+00    1.50944682e+00   |   7.92538896e+00   -7.75734393e+00    1.50944682e+00   
  7   -8.08267874e+00    7.55344947e+00   -1.97727978e+00   |  -8.08267874e+00    7.55344947e+00   -1.97727978e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = TTT   (Configuration in file "config-Cr-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -54.82149220556308
2^p V(r_1,...,r_N)    = -54.82149220556508

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
  1    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
  2    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
  3   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
  4   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
  5    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
  6    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
  7   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
  8   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
  9    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 10    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 11   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
 12   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
 13    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 14    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 15   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
 16   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
 17    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 18    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 19   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
 20   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
 21    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 22    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 23   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
 24   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
 25    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 26    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 27   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
 28   -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   |  -5.22809172e+00   -5.92765341e+00   -9.79399236e+00   
 29    3.15310187e+00    1.54952660e+00   -3.21466207e+00   |   3.15310187e+00    1.54952660e+00   -3.21466207e+00   
 30    6.54766365e+00   -2.08072561e+00    6.39985021e+00   |   6.54766365e+00   -2.08072561e+00    6.39985021e+00   
 31   -4.47267380e+00    6.45885242e+00    6.60880422e+00   |  -4.47267380e+00    6.45885242e+00    6.60880422e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = TTF   (Configuration in file "config-Cr-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -1.7168096422961379
2^p V(r_1,...,r_N)    = -1.7168096422960595

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -7.78988968e+00    4.52444418e+00   -1.18383850e+01   |  -7.78988968e+00    4.52444418e+00   -1.18383850e+01   
  1    5.81145600e+00   -3.63005320e+00   -1.00963523e+01   |   5.81145600e+00   -3.63005320e+00   -1.00963523e+01   
  2    8.56214490e+00    6.39342847e+00    1.19763935e+01   |   8.56214490e+00    6.39342847e+00    1.19763935e+01   
  3   -6.58371122e+00   -7.28781945e+00    9.95834385e+00   |  -6.58371122e+00   -7.28781945e+00    9.95834385e+00   
  4   -7.78988968e+00    4.52444418e+00   -1.18383850e+01   |  -7.78988968e+00    4.52444418e+00   -1.18383850e+01   
  5    5.81145600e+00   -3.63005320e+00   -1.00963523e+01   |   5.81145600e+00   -3.63005320e+00   -1.00963523e+01   
  6    8.56214490e+00    6.39342847e+00    1.19763935e+01   |   8.56214490e+00    6.39342847e+00    1.19763935e+01   
  7   -6.58371122e+00   -7.28781945e+00    9.95834385e+00   |  -6.58371122e+00   -7.28781945e+00    9.95834385e+00   
  8   -7.78988968e+00    4.52444418e+00   -1.18383850e+01   |  -7.78988968e+00    4.52444418e+00   -1.18383850e+01   
  9    5.81145600e+00   -3.63005320e+00   -1.00963523e+01   |   5.81145600e+00   -3.63005320e+00   -1.00963523e+01   
 10    8.56214490e+00    6.39342847e+00    1.19763935e+01   |   8.56214490e+00    6.39342847e+00    1.19763935e+01   
 11   -6.58371122e+00   -7.28781945e+00    9.95834385e+00   |  -6.58371122e+00   -7.28781945e+00    9.95834385e+00   
 12   -7.78988968e+00    4.52444418e+00   -1.18383850e+01   |  -7.78988968e+00    4.52444418e+00   -1.18383850e+01   
 13    5.81145600e+00   -3.63005320e+00   -1.00963523e+01   |   5.81145600e+00   -3.63005320e+00   -1.00963523e+01   
 14    8.56214490e+00    6.39342847e+00    1.19763935e+01   |   8.56214490e+00    6.39342847e+00    1.19763935e+01   
 15   -6.58371122e+00   -7.28781945e+00    9.95834385e+00   |  -6.58371122e+00   -7.28781945e+00    9.95834385e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = TFT   (Configuration in file "config-Cr-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -6.303679730069255
2^p V(r_1,...,r_N)    = -6.303679730069212

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   |  -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   
  1    8.79966798e-01    1.74524492e+01   -1.33236132e+01   |   8.79966798e-01    1.74524492e+01   -1.33236132e+01   
  2    2.94804008e+00   -1.73256730e+01    1.17705809e+01   |   2.94804008e+00   -1.73256730e+01    1.17705809e+01   
  3   -1.51889929e+00    9.53719251e+00    4.79872405e+00   |  -1.51889929e+00    9.53719251e+00    4.79872405e+00   
  4   -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   |  -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   
  5    8.79966798e-01    1.74524492e+01   -1.33236132e+01   |   8.79966798e-01    1.74524492e+01   -1.33236132e+01   
  6    2.94804008e+00   -1.73256730e+01    1.17705809e+01   |   2.94804008e+00   -1.73256730e+01    1.17705809e+01   
  7   -1.51889929e+00    9.53719251e+00    4.79872405e+00   |  -1.51889929e+00    9.53719251e+00    4.79872405e+00   
  8   -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   |  -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   
  9    8.79966798e-01    1.74524492e+01   -1.33236132e+01   |   8.79966798e-01    1.74524492e+01   -1.33236132e+01   
 10    2.94804008e+00   -1.73256730e+01    1.17705809e+01   |   2.94804008e+00   -1.73256730e+01    1.17705809e+01   
 11   -1.51889929e+00    9.53719251e+00    4.79872405e+00   |  -1.51889929e+00    9.53719251e+00    4.79872405e+00   
 12   -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   |  -2.30910758e+00   -9.66396872e+00   -3.24569178e+00   
 13    8.79966798e-01    1.74524492e+01   -1.33236132e+01   |   8.79966798e-01    1.74524492e+01   -1.33236132e+01   
 14    2.94804008e+00   -1.73256730e+01    1.17705809e+01   |   2.94804008e+00   -1.73256730e+01    1.17705809e+01   
 15   -1.51889929e+00    9.53719251e+00    4.79872405e+00   |  -1.51889929e+00    9.53719251e+00    4.79872405e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = TFF   (Configuration in file "config-Cr-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -4.406806361091495
2^p V(r_1,...,r_N)    = -4.406806361091505

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.77693573e+00   -6.70394116e+00   -7.20418144e+00   |  -1.77693573e+00   -6.70394116e+00   -7.20418144e+00   
  1   -7.66142428e-01    7.42433866e+00   -7.34280079e+00   |  -7.66142428e-01    7.42433866e+00   -7.34280079e+00   
  2   -1.79379526e+00   -8.29385082e+00    7.48478997e+00   |  -1.79379526e+00   -8.29385082e+00    7.48478997e+00   
  3    4.33687341e+00    7.57345332e+00    7.06219226e+00   |   4.33687341e+00    7.57345332e+00    7.06219226e+00   
  4   -1.77693573e+00   -6.70394116e+00   -7.20418144e+00   |  -1.77693573e+00   -6.70394116e+00   -7.20418144e+00   
  5   -7.66142428e-01    7.42433866e+00   -7.34280079e+00   |  -7.66142428e-01    7.42433866e+00   -7.34280079e+00   
  6   -1.79379526e+00   -8.29385082e+00    7.48478997e+00   |  -1.79379526e+00   -8.29385082e+00    7.48478997e+00   
  7    4.33687341e+00    7.57345332e+00    7.06219226e+00   |   4.33687341e+00    7.57345332e+00    7.06219226e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = FTT   (Configuration in file "config-Cr-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 33.55390410980131
2^p V(r_1,...,r_N)    = 33.55390410980138

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -3.41042992e+01   -7.69595078e+00    2.83464328e+01   |  -3.41042992e+01   -7.69595078e+00    2.83464328e+01   
  1    1.15681033e+01    5.20893061e+00    1.17962584e+00   |   1.15681033e+01    5.20893061e+00    1.17962584e+00   
  2    3.42866967e+01    8.50387713e-01   -2.59895904e+01   |   3.42866967e+01    8.50387713e-01   -2.59895904e+01   
  3   -1.17505008e+01    1.63663246e+00   -3.53646823e+00   |  -1.17505008e+01    1.63663246e+00   -3.53646823e+00   
  4   -3.41042992e+01   -7.69595078e+00    2.83464328e+01   |  -3.41042992e+01   -7.69595078e+00    2.83464328e+01   
  5    1.15681033e+01    5.20893061e+00    1.17962584e+00   |   1.15681033e+01    5.20893061e+00    1.17962584e+00   
  6    3.42866967e+01    8.50387713e-01   -2.59895904e+01   |   3.42866967e+01    8.50387713e-01   -2.59895904e+01   
  7   -1.17505008e+01    1.63663246e+00   -3.53646823e+00   |  -1.17505008e+01    1.63663246e+00   -3.53646823e+00   
  8   -3.41042992e+01   -7.69595078e+00    2.83464328e+01   |  -3.41042992e+01   -7.69595078e+00    2.83464328e+01   
  9    1.15681033e+01    5.20893061e+00    1.17962584e+00   |   1.15681033e+01    5.20893061e+00    1.17962584e+00   
 10    3.42866967e+01    8.50387713e-01   -2.59895904e+01   |   3.42866967e+01    8.50387713e-01   -2.59895904e+01   
 11   -1.17505008e+01    1.63663246e+00   -3.53646823e+00   |  -1.17505008e+01    1.63663246e+00   -3.53646823e+00   
 12   -3.41042992e+01   -7.69595078e+00    2.83464328e+01   |  -3.41042992e+01   -7.69595078e+00    2.83464328e+01   
 13    1.15681033e+01    5.20893061e+00    1.17962584e+00   |   1.15681033e+01    5.20893061e+00    1.17962584e+00   
 14    3.42866967e+01    8.50387713e-01   -2.59895904e+01   |   3.42866967e+01    8.50387713e-01   -2.59895904e+01   
 15   -1.17505008e+01    1.63663246e+00   -3.53646823e+00   |  -1.17505008e+01    1.63663246e+00   -3.53646823e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = FTF   (Configuration in file "config-Cr-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 2.806889078840211
2^p V(r_1,...,r_N)    = 2.8068890788402103

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -9.80766237e+00   -3.44824882e+00   -9.05117195e+00   |  -9.80766237e+00   -3.44824882e+00   -9.05117195e+00   
  1    1.18344696e+01    4.75467854e+00   -8.54321597e+00   |   1.18344696e+01    4.75467854e+00   -8.54321597e+00   
  2    7.37137006e+00   -3.44601398e+00    9.58628129e+00   |   7.37137006e+00   -3.44601398e+00    9.58628129e+00   
  3   -9.39817734e+00    2.13958427e+00    8.00810663e+00   |  -9.39817734e+00    2.13958427e+00    8.00810663e+00   
  4   -9.80766237e+00   -3.44824882e+00   -9.05117195e+00   |  -9.80766237e+00   -3.44824882e+00   -9.05117195e+00   
  5    1.18344696e+01    4.75467854e+00   -8.54321597e+00   |   1.18344696e+01    4.75467854e+00   -8.54321597e+00   
  6    7.37137006e+00   -3.44601398e+00    9.58628129e+00   |   7.37137006e+00   -3.44601398e+00    9.58628129e+00   
  7   -9.39817734e+00    2.13958427e+00    8.00810663e+00   |  -9.39817734e+00    2.13958427e+00    8.00810663e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cr, PBC = FFT   (Configuration in file "config-Cr-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -2.6562483483078116
2^p V(r_1,...,r_N)    = -2.6562483483078005

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -6.75444705e+00   -9.12410428e+00    3.31418478e+00   |  -6.75444705e+00   -9.12410428e+00    3.31418478e+00   
  1    7.46724680e+00    8.48555720e+00    3.30881496e+00   |   7.46724680e+00    8.48555720e+00    3.30881496e+00   
  2    8.07857092e+00   -6.43846918e+00   -1.15904454e+00   |   8.07857092e+00   -6.43846918e+00   -1.15904454e+00   
  3   -8.79137068e+00    7.07701626e+00   -5.46395521e+00   |  -8.79137068e+00    7.07701626e+00   -5.46395521e+00   
  4   -6.75444705e+00   -9.12410428e+00    3.31418478e+00   |  -6.75444705e+00   -9.12410428e+00    3.31418478e+00   
  5    7.46724680e+00    8.48555720e+00    3.30881496e+00   |   7.46724680e+00    8.48555720e+00    3.30881496e+00   
  6    8.07857092e+00   -6.43846918e+00   -1.15904454e+00   |   8.07857092e+00   -6.43846918e+00   -1.15904454e+00   
  7   -8.79137068e+00    7.07701626e+00   -5.46395521e+00   |  -8.79137068e+00    7.07701626e+00   -5.46395521e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = TTT   (Configuration in file "config-Cu-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 2.0393513905422505
2^p V(r_1,...,r_N)    = 2.0393513905426706

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
  1    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
  2    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
  3   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
  4   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
  5    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
  6    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
  7   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
  8   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
  9    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 10    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 11   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
 12   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
 13    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 14    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 15   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
 16   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
 17    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 18    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 19   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
 20   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
 21    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 22    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 23   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
 24   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
 25    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 26    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 27   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
 28   -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   |  -4.08695565e+00   -3.26436184e+00   -4.85263876e+00   
 29    5.90187497e+00    2.63086666e+00   -4.40152236e+00   |   5.90187497e+00    2.63086666e+00   -4.40152236e+00   
 30    6.11683930e+00   -7.15770484e+00    6.08009786e+00   |   6.11683930e+00   -7.15770484e+00    6.08009786e+00   
 31   -7.93175862e+00    7.79120001e+00    3.17406326e+00   |  -7.93175862e+00    7.79120001e+00    3.17406326e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = TTF   (Configuration in file "config-Cu-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 9.097031877454489
2^p V(r_1,...,r_N)    = 9.097031877454512

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    4.65889683e+00    4.27863788e+00   -1.08360774e+01   |   4.65889683e+00    4.27863788e+00   -1.08360774e+01   
  1   -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   |  -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   
  2    1.64117901e+00    2.08653789e+00    9.16822815e+00   |   1.64117901e+00    2.08653789e+00    9.16822815e+00   
  3   -1.22853277e+00   -3.37217313e+00    1.10372746e+01   |  -1.22853277e+00   -3.37217313e+00    1.10372746e+01   
  4    4.65889683e+00    4.27863788e+00   -1.08360774e+01   |   4.65889683e+00    4.27863788e+00   -1.08360774e+01   
  5   -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   |  -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   
  6    1.64117901e+00    2.08653789e+00    9.16822815e+00   |   1.64117901e+00    2.08653789e+00    9.16822815e+00   
  7   -1.22853277e+00   -3.37217313e+00    1.10372746e+01   |  -1.22853277e+00   -3.37217313e+00    1.10372746e+01   
  8    4.65889683e+00    4.27863788e+00   -1.08360774e+01   |   4.65889683e+00    4.27863788e+00   -1.08360774e+01   
  9   -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   |  -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   
 10    1.64117901e+00    2.08653789e+00    9.16822815e+00   |   1.64117901e+00    2.08653789e+00    9.16822815e+00   
 11   -1.22853277e+00   -3.37217313e+00    1.10372746e+01   |  -1.22853277e+00   -3.37217313e+00    1.10372746e+01   
 12    4.65889683e+00    4.27863788e+00   -1.08360774e+01   |   4.65889683e+00    4.27863788e+00   -1.08360774e+01   
 13   -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   |  -5.07154307e+00   -2.99300264e+00   -9.36942540e+00   
 14    1.64117901e+00    2.08653789e+00    9.16822815e+00   |   1.64117901e+00    2.08653789e+00    9.16822815e+00   
 15   -1.22853277e+00   -3.37217313e+00    1.10372746e+01   |  -1.22853277e+00   -3.37217313e+00    1.10372746e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = TFT   (Configuration in file "config-Cu-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 6.518627117933562
2^p V(r_1,...,r_N)    = 6.518627117933544

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    1.17891576e+01   -9.79048419e+00    1.07562062e+01   |   1.17891576e+01   -9.79048419e+00    1.07562062e+01   
  1   -3.42912252e+00    1.00899872e+01    7.10037292e+00   |  -3.42912252e+00    1.00899872e+01    7.10037292e+00   
  2   -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   |  -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   
  3    2.02967200e+00    8.68892842e+00   -5.99539795e+00   |   2.02967200e+00    8.68892842e+00   -5.99539795e+00   
  4    1.17891576e+01   -9.79048419e+00    1.07562062e+01   |   1.17891576e+01   -9.79048419e+00    1.07562062e+01   
  5   -3.42912252e+00    1.00899872e+01    7.10037292e+00   |  -3.42912252e+00    1.00899872e+01    7.10037292e+00   
  6   -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   |  -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   
  7    2.02967200e+00    8.68892842e+00   -5.99539795e+00   |   2.02967200e+00    8.68892842e+00   -5.99539795e+00   
  8    1.17891576e+01   -9.79048419e+00    1.07562062e+01   |   1.17891576e+01   -9.79048419e+00    1.07562062e+01   
  9   -3.42912252e+00    1.00899872e+01    7.10037292e+00   |  -3.42912252e+00    1.00899872e+01    7.10037292e+00   
 10   -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   |  -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   
 11    2.02967200e+00    8.68892842e+00   -5.99539795e+00   |   2.02967200e+00    8.68892842e+00   -5.99539795e+00   
 12    1.17891576e+01   -9.79048419e+00    1.07562062e+01   |   1.17891576e+01   -9.79048419e+00    1.07562062e+01   
 13   -3.42912252e+00    1.00899872e+01    7.10037292e+00   |  -3.42912252e+00    1.00899872e+01    7.10037292e+00   
 14   -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   |  -1.03897071e+01   -8.98843142e+00   -1.18611812e+01   
 15    2.02967200e+00    8.68892842e+00   -5.99539795e+00   |   2.02967200e+00    8.68892842e+00   -5.99539795e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = TFF   (Configuration in file "config-Cu-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -4.615990920779374
2^p V(r_1,...,r_N)    = -4.615990920779364

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -8.02148643e-01   -7.80477878e+00   -7.33568220e+00   |  -8.02148643e-01   -7.80477878e+00   -7.33568220e+00   
  1    1.69082580e+00    7.43781073e+00   -7.13397527e+00   |   1.69082580e+00    7.43781073e+00   -7.13397527e+00   
  2    8.84345591e-01   -7.45824159e+00    7.80749182e+00   |   8.84345591e-01   -7.45824159e+00    7.80749182e+00   
  3   -1.77302275e+00    7.82520963e+00    6.66216564e+00   |  -1.77302275e+00    7.82520963e+00    6.66216564e+00   
  4   -8.02148643e-01   -7.80477878e+00   -7.33568220e+00   |  -8.02148643e-01   -7.80477878e+00   -7.33568220e+00   
  5    1.69082580e+00    7.43781073e+00   -7.13397527e+00   |   1.69082580e+00    7.43781073e+00   -7.13397527e+00   
  6    8.84345591e-01   -7.45824159e+00    7.80749182e+00   |   8.84345591e-01   -7.45824159e+00    7.80749182e+00   
  7   -1.77302275e+00    7.82520963e+00    6.66216564e+00   |  -1.77302275e+00    7.82520963e+00    6.66216564e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = FTT   (Configuration in file "config-Cu-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -4.907927530993903
2^p V(r_1,...,r_N)    = -4.907927530993898

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -8.78122623e+00    4.04898072e+00    4.61162809e-01   |  -8.78122623e+00    4.04898072e+00    4.61162809e-01   
  1    1.04507292e+01   -2.10533498e+00    5.76631049e+00   |   1.04507292e+01   -2.10533498e+00    5.76631049e+00   
  2    9.70024439e+00    1.31383041e+00   -2.18640023e+00   |   9.70024439e+00    1.31383041e+00   -2.18640023e+00   
  3   -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   |  -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   
  4   -8.78122623e+00    4.04898072e+00    4.61162809e-01   |  -8.78122623e+00    4.04898072e+00    4.61162809e-01   
  5    1.04507292e+01   -2.10533498e+00    5.76631049e+00   |   1.04507292e+01   -2.10533498e+00    5.76631049e+00   
  6    9.70024439e+00    1.31383041e+00   -2.18640023e+00   |   9.70024439e+00    1.31383041e+00   -2.18640023e+00   
  7   -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   |  -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   
  8   -8.78122623e+00    4.04898072e+00    4.61162809e-01   |  -8.78122623e+00    4.04898072e+00    4.61162809e-01   
  9    1.04507292e+01   -2.10533498e+00    5.76631049e+00   |   1.04507292e+01   -2.10533498e+00    5.76631049e+00   
 10    9.70024439e+00    1.31383041e+00   -2.18640023e+00   |   9.70024439e+00    1.31383041e+00   -2.18640023e+00   
 11   -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   |  -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   
 12   -8.78122623e+00    4.04898072e+00    4.61162809e-01   |  -8.78122623e+00    4.04898072e+00    4.61162809e-01   
 13    1.04507292e+01   -2.10533498e+00    5.76631049e+00   |   1.04507292e+01   -2.10533498e+00    5.76631049e+00   
 14    9.70024439e+00    1.31383041e+00   -2.18640023e+00   |   9.70024439e+00    1.31383041e+00   -2.18640023e+00   
 15   -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   |  -1.13697474e+01   -3.25747615e+00   -4.04107307e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = FTF   (Configuration in file "config-Cu-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 33.71115093438778
2^p V(r_1,...,r_N)    = 33.71115093438779

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.77481614e+01   -1.38675722e+01   -2.96645184e+01   |  -1.77481614e+01   -1.38675722e+01   -2.96645184e+01   
  1    1.43705313e+01   -2.94098788e+01   -4.03766159e+01   |   1.43705313e+01   -2.94098788e+01   -4.03766159e+01   
  2    1.37584770e+01    2.83290566e+01    4.32544086e+01   |   1.37584770e+01    2.83290566e+01    4.32544086e+01   
  3   -1.03808470e+01    1.49483943e+01    2.67867257e+01   |  -1.03808470e+01    1.49483943e+01    2.67867257e+01   
  4   -1.77481614e+01   -1.38675722e+01   -2.96645184e+01   |  -1.77481614e+01   -1.38675722e+01   -2.96645184e+01   
  5    1.43705313e+01   -2.94098788e+01   -4.03766159e+01   |   1.43705313e+01   -2.94098788e+01   -4.03766159e+01   
  6    1.37584770e+01    2.83290566e+01    4.32544086e+01   |   1.37584770e+01    2.83290566e+01    4.32544086e+01   
  7   -1.03808470e+01    1.49483943e+01    2.67867257e+01   |  -1.03808470e+01    1.49483943e+01    2.67867257e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Cu, PBC = FFT   (Configuration in file "config-Cu-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -10.668522744230597
2^p V(r_1,...,r_N)    = -10.668522744230582

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -5.68563955e+00   -6.54429034e+00   -2.62144736e+00   |  -5.68563955e+00   -6.54429034e+00   -2.62144736e+00   
  1    5.99857176e+00    6.43247380e+00   -3.10786193e+00   |   5.99857176e+00    6.43247380e+00   -3.10786193e+00   
  2    4.12342207e+00   -5.23366567e+00    2.17623532e+00   |   4.12342207e+00   -5.23366567e+00    2.17623532e+00   
  3   -4.43635429e+00    5.34548220e+00    3.55307397e+00   |  -4.43635429e+00    5.34548220e+00    3.55307397e+00   
  4   -5.68563955e+00   -6.54429034e+00   -2.62144736e+00   |  -5.68563955e+00   -6.54429034e+00   -2.62144736e+00   
  5    5.99857176e+00    6.43247380e+00   -3.10786193e+00   |   5.99857176e+00    6.43247380e+00   -3.10786193e+00   
  6    4.12342207e+00   -5.23366567e+00    2.17623532e+00   |   4.12342207e+00   -5.23366567e+00    2.17623532e+00   
  7   -4.43635429e+00    5.34548220e+00    3.55307397e+00   |  -4.43635429e+00    5.34548220e+00    3.55307397e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = TTT   (Configuration in file "config-Fe-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -137.04328665066404
2^p V(r_1,...,r_N)    = -137.04328665066276

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
  1    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
  2    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
  3   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
  4   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
  5    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
  6    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
  7   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
  8   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
  9    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 10    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 11   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
 12   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
 13    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 14    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 15   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
 16   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
 17    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 18    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 19   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
 20   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
 21    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 22    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 23   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
 24   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
 25    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 26    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 27   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
 28   -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   |  -6.17460625e+00   -1.25920184e+01   -2.76732938e+00   
 29    3.54102781e+00    9.50601977e+00    1.98209867e+00   |   3.54102781e+00    9.50601977e+00    1.98209867e+00   
 30    7.70140048e+00   -2.93417184e+00   -2.92811141e+00   |   7.70140048e+00   -2.93417184e+00   -2.92811141e+00   
 31   -5.06782204e+00    6.02017046e+00    3.71334212e+00   |  -5.06782204e+00    6.02017046e+00    3.71334212e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = TTF   (Configuration in file "config-Fe-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 15.849827709968812
2^p V(r_1,...,r_N)    = 15.849827709968725

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    1.80747900e+00   -1.00482070e+01   -1.63857631e+01   |   1.80747900e+00   -1.00482070e+01   -1.63857631e+01   
  1   -1.33597223e+00    9.19928329e+00   -1.49009917e+01   |  -1.33597223e+00    9.19928329e+00   -1.49009917e+01   
  2   -3.41331791e+00   -8.21057448e+00    1.44898689e+01   |  -3.41331791e+00   -8.21057448e+00    1.44898689e+01   
  3    2.94181115e+00    9.05949817e+00    1.67968859e+01   |   2.94181115e+00    9.05949817e+00    1.67968859e+01   
  4    1.80747900e+00   -1.00482070e+01   -1.63857631e+01   |   1.80747900e+00   -1.00482070e+01   -1.63857631e+01   
  5   -1.33597223e+00    9.19928329e+00   -1.49009917e+01   |  -1.33597223e+00    9.19928329e+00   -1.49009917e+01   
  6   -3.41331791e+00   -8.21057448e+00    1.44898689e+01   |  -3.41331791e+00   -8.21057448e+00    1.44898689e+01   
  7    2.94181115e+00    9.05949817e+00    1.67968859e+01   |   2.94181115e+00    9.05949817e+00    1.67968859e+01   
  8    1.80747900e+00   -1.00482070e+01   -1.63857631e+01   |   1.80747900e+00   -1.00482070e+01   -1.63857631e+01   
  9   -1.33597223e+00    9.19928329e+00   -1.49009917e+01   |  -1.33597223e+00    9.19928329e+00   -1.49009917e+01   
 10   -3.41331791e+00   -8.21057448e+00    1.44898689e+01   |  -3.41331791e+00   -8.21057448e+00    1.44898689e+01   
 11    2.94181115e+00    9.05949817e+00    1.67968859e+01   |   2.94181115e+00    9.05949817e+00    1.67968859e+01   
 12    1.80747900e+00   -1.00482070e+01   -1.63857631e+01   |   1.80747900e+00   -1.00482070e+01   -1.63857631e+01   
 13   -1.33597223e+00    9.19928329e+00   -1.49009917e+01   |  -1.33597223e+00    9.19928329e+00   -1.49009917e+01   
 14   -3.41331791e+00   -8.21057448e+00    1.44898689e+01   |  -3.41331791e+00   -8.21057448e+00    1.44898689e+01   
 15    2.94181115e+00    9.05949817e+00    1.67968859e+01   |   2.94181115e+00    9.05949817e+00    1.67968859e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = TFT   (Configuration in file "config-Fe-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -8.848467361553292
2^p V(r_1,...,r_N)    = -8.848467361553368

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   |  -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   
  1   -3.48800870e+00    1.30501317e+01   -3.26990572e+00   |  -3.48800870e+00    1.30501317e+01   -3.26990572e+00   
  2   -9.50443194e-01   -1.18872251e+01    6.27404111e+00   |  -9.50443194e-01   -1.18872251e+01    6.27404111e+00   
  3    4.48995201e+00    1.05704847e+01    4.40769074e+00   |   4.48995201e+00    1.05704847e+01    4.40769074e+00   
  4   -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   |  -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   
  5   -3.48800870e+00    1.30501317e+01   -3.26990572e+00   |  -3.48800870e+00    1.30501317e+01   -3.26990572e+00   
  6   -9.50443194e-01   -1.18872251e+01    6.27404111e+00   |  -9.50443194e-01   -1.18872251e+01    6.27404111e+00   
  7    4.48995201e+00    1.05704847e+01    4.40769074e+00   |   4.48995201e+00    1.05704847e+01    4.40769074e+00   
  8   -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   |  -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   
  9   -3.48800870e+00    1.30501317e+01   -3.26990572e+00   |  -3.48800870e+00    1.30501317e+01   -3.26990572e+00   
 10   -9.50443194e-01   -1.18872251e+01    6.27404111e+00   |  -9.50443194e-01   -1.18872251e+01    6.27404111e+00   
 11    4.48995201e+00    1.05704847e+01    4.40769074e+00   |   4.48995201e+00    1.05704847e+01    4.40769074e+00   
 12   -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   |  -5.15001160e-02   -1.17333913e+01   -7.41182613e+00   
 13   -3.48800870e+00    1.30501317e+01   -3.26990572e+00   |  -3.48800870e+00    1.30501317e+01   -3.26990572e+00   
 14   -9.50443194e-01   -1.18872251e+01    6.27404111e+00   |  -9.50443194e-01   -1.18872251e+01    6.27404111e+00   
 15    4.48995201e+00    1.05704847e+01    4.40769074e+00   |   4.48995201e+00    1.05704847e+01    4.40769074e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = TFF   (Configuration in file "config-Fe-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -8.611707633518726
2^p V(r_1,...,r_N)    = -8.611707633518721

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    5.67880337e+00   -8.29901416e+00   -9.47386222e+00   |   5.67880337e+00   -8.29901416e+00   -9.47386222e+00   
  1   -3.85638267e+00    1.01690529e+01   -1.09671373e+01   |  -3.85638267e+00    1.01690529e+01   -1.09671373e+01   
  2   -4.21394498e+00   -1.12098798e+01    9.41094034e+00   |  -4.21394498e+00   -1.12098798e+01    9.41094034e+00   
  3    2.39152428e+00    9.33984111e+00    1.10300591e+01   |   2.39152428e+00    9.33984111e+00    1.10300591e+01   
  4    5.67880337e+00   -8.29901416e+00   -9.47386222e+00   |   5.67880337e+00   -8.29901416e+00   -9.47386222e+00   
  5   -3.85638267e+00    1.01690529e+01   -1.09671373e+01   |  -3.85638267e+00    1.01690529e+01   -1.09671373e+01   
  6   -4.21394498e+00   -1.12098798e+01    9.41094034e+00   |  -4.21394498e+00   -1.12098798e+01    9.41094034e+00   
  7    2.39152428e+00    9.33984111e+00    1.10300591e+01   |   2.39152428e+00    9.33984111e+00    1.10300591e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = FTT   (Configuration in file "config-Fe-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -0.4536428586263108
2^p V(r_1,...,r_N)    = -0.4536428586263394

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.50326406e+01   -2.52471129e+00    2.62192809e+00   |  -1.50326406e+01   -2.52471129e+00    2.62192809e+00   
  1    1.33696886e+01    3.79229788e+00    1.57703983e+00   |   1.33696886e+01    3.79229788e+00    1.57703983e+00   
  2    1.65890510e+01   -4.88901514e+00   -2.62186385e+00   |   1.65890510e+01   -4.88901514e+00   -2.62186385e+00   
  3   -1.49260989e+01    3.62142856e+00   -1.57710406e+00   |  -1.49260989e+01    3.62142856e+00   -1.57710406e+00   
  4   -1.50326406e+01   -2.52471129e+00    2.62192809e+00   |  -1.50326406e+01   -2.52471129e+00    2.62192809e+00   
  5    1.33696886e+01    3.79229788e+00    1.57703983e+00   |   1.33696886e+01    3.79229788e+00    1.57703983e+00   
  6    1.65890510e+01   -4.88901514e+00   -2.62186385e+00   |   1.65890510e+01   -4.88901514e+00   -2.62186385e+00   
  7   -1.49260989e+01    3.62142856e+00   -1.57710406e+00   |  -1.49260989e+01    3.62142856e+00   -1.57710406e+00   
  8   -1.50326406e+01   -2.52471129e+00    2.62192809e+00   |  -1.50326406e+01   -2.52471129e+00    2.62192809e+00   
  9    1.33696886e+01    3.79229788e+00    1.57703983e+00   |   1.33696886e+01    3.79229788e+00    1.57703983e+00   
 10    1.65890510e+01   -4.88901514e+00   -2.62186385e+00   |   1.65890510e+01   -4.88901514e+00   -2.62186385e+00   
 11   -1.49260989e+01    3.62142856e+00   -1.57710406e+00   |  -1.49260989e+01    3.62142856e+00   -1.57710406e+00   
 12   -1.50326406e+01   -2.52471129e+00    2.62192809e+00   |  -1.50326406e+01   -2.52471129e+00    2.62192809e+00   
 13    1.33696886e+01    3.79229788e+00    1.57703983e+00   |   1.33696886e+01    3.79229788e+00    1.57703983e+00   
 14    1.65890510e+01   -4.88901514e+00   -2.62186385e+00   |   1.65890510e+01   -4.88901514e+00   -2.62186385e+00   
 15   -1.49260989e+01    3.62142856e+00   -1.57710406e+00   |  -1.49260989e+01    3.62142856e+00   -1.57710406e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = FTF   (Configuration in file "config-Fe-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 16.47725830432655
2^p V(r_1,...,r_N)    = 16.47725830432657

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.86753603e+01    9.73025980e+00   -1.24397960e+01   |  -1.86753603e+01    9.73025980e+00   -1.24397960e+01   
  1    1.62417036e+01   -9.09550649e+00   -1.24403654e+01   |   1.62417036e+01   -9.09550649e+00   -1.24403654e+01   
  2    1.44836119e+01    3.29226460e+00    1.26090118e+01   |   1.44836119e+01    3.29226460e+00    1.26090118e+01   
  3   -1.20499553e+01   -3.92701791e+00    1.22711496e+01   |  -1.20499553e+01   -3.92701791e+00    1.22711496e+01   
  4   -1.86753603e+01    9.73025980e+00   -1.24397960e+01   |  -1.86753603e+01    9.73025980e+00   -1.24397960e+01   
  5    1.62417036e+01   -9.09550649e+00   -1.24403654e+01   |   1.62417036e+01   -9.09550649e+00   -1.24403654e+01   
  6    1.44836119e+01    3.29226460e+00    1.26090118e+01   |   1.44836119e+01    3.29226460e+00    1.26090118e+01   
  7   -1.20499553e+01   -3.92701791e+00    1.22711496e+01   |  -1.20499553e+01   -3.92701791e+00    1.22711496e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Fe, PBC = FFT   (Configuration in file "config-Fe-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -1.941603868450864
2^p V(r_1,...,r_N)    = -1.9416038684508592

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -9.57364414e+00   -1.29768166e+01    3.31821923e+00   |  -9.57364414e+00   -1.29768166e+01    3.31821923e+00   
  1    1.00418407e+01    1.16646560e+01    2.65554439e+00   |   1.00418407e+01    1.16646560e+01    2.65554439e+00   
  2    1.10211225e+01   -9.10688855e+00   -5.06925524e+00   |   1.10211225e+01   -9.10688855e+00   -5.06925524e+00   
  3   -1.14893190e+01    1.04190491e+01   -9.04508381e-01   |  -1.14893190e+01    1.04190491e+01   -9.04508381e-01   
  4   -9.57364414e+00   -1.29768166e+01    3.31821923e+00   |  -9.57364414e+00   -1.29768166e+01    3.31821923e+00   
  5    1.00418407e+01    1.16646560e+01    2.65554439e+00   |   1.00418407e+01    1.16646560e+01    2.65554439e+00   
  6    1.10211225e+01   -9.10688855e+00   -5.06925524e+00   |   1.10211225e+01   -9.10688855e+00   -5.06925524e+00   
  7   -1.14893190e+01    1.04190491e+01   -9.04508381e-01   |  -1.14893190e+01    1.04190491e+01   -9.04508381e-01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = TTT   (Configuration in file "config-Ni-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -8.088233111998127
2^p V(r_1,...,r_N)    = -8.088233111999127

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
  1   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
  2   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
  3    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
  4    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
  5   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
  6   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
  7    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
  8    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
  9   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 10   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 11    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
 12    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
 13   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 14   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 15    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
 16    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
 17   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 18   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 19    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
 20    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
 21   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 22   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 23    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
 24    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
 25   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 26   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 27    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
 28    1.80440541e+01    1.45937791e+01   -2.54250152e+01   |   1.80440541e+01    1.45937791e+01   -2.54250152e+01   
 29   -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   |  -8.15482643e+00   -5.05784245e+00   -2.38890410e+00   
 30   -2.20110450e+01    7.03716593e+00    1.59448094e+01   |  -2.20110450e+01    7.03716593e+00    1.59448094e+01   
 31    1.21218173e+01   -1.65731026e+01    1.18691099e+01   |   1.21218173e+01   -1.65731026e+01    1.18691099e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = TTF   (Configuration in file "config-Ni-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -12.341195316780865
2^p V(r_1,...,r_N)    = -12.34119531678081

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    1.24221989e+00    1.80211322e+00   -1.07248118e+01   |   1.24221989e+00    1.80211322e+00   -1.07248118e+01   
  1   -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   |  -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   
  2    3.17704670e+00   -2.09854097e+00    9.70010504e+00   |   3.17704670e+00   -2.09854097e+00    9.70010504e+00   
  3   -2.45233738e+00    2.10932814e+00    1.04232087e+01   |  -2.45233738e+00    2.10932814e+00    1.04232087e+01   
  4    1.24221989e+00    1.80211322e+00   -1.07248118e+01   |   1.24221989e+00    1.80211322e+00   -1.07248118e+01   
  5   -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   |  -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   
  6    3.17704670e+00   -2.09854097e+00    9.70010504e+00   |   3.17704670e+00   -2.09854097e+00    9.70010504e+00   
  7   -2.45233738e+00    2.10932814e+00    1.04232087e+01   |  -2.45233738e+00    2.10932814e+00    1.04232087e+01   
  8    1.24221989e+00    1.80211322e+00   -1.07248118e+01   |   1.24221989e+00    1.80211322e+00   -1.07248118e+01   
  9   -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   |  -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   
 10    3.17704670e+00   -2.09854097e+00    9.70010504e+00   |   3.17704670e+00   -2.09854097e+00    9.70010504e+00   
 11   -2.45233738e+00    2.10932814e+00    1.04232087e+01   |  -2.45233738e+00    2.10932814e+00    1.04232087e+01   
 12    1.24221989e+00    1.80211322e+00   -1.07248118e+01   |   1.24221989e+00    1.80211322e+00   -1.07248118e+01   
 13   -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   |  -1.96692921e+00   -1.81290038e+00   -9.39850195e+00   
 14    3.17704670e+00   -2.09854097e+00    9.70010504e+00   |   3.17704670e+00   -2.09854097e+00    9.70010504e+00   
 15   -2.45233738e+00    2.10932814e+00    1.04232087e+01   |  -2.45233738e+00    2.10932814e+00    1.04232087e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = TFT   (Configuration in file "config-Ni-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 7.075308882322114
2^p V(r_1,...,r_N)    = 7.075308882322216

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0    2.97905391e+01   -9.90210044e+00    3.25396055e+01   |   2.97905391e+01   -9.90210044e+00    3.25396055e+01   
  1    4.83055696e+00    6.12434611e+00    8.67182283e+00   |   4.83055696e+00    6.12434611e+00    8.67182283e+00   
  2   -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   |  -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   
  3   -2.06502695e+00    8.45297254e+00   -8.84652061e+00   |  -2.06502695e+00    8.45297254e+00   -8.84652061e+00   
  4    2.97905391e+01   -9.90210044e+00    3.25396055e+01   |   2.97905391e+01   -9.90210044e+00    3.25396055e+01   
  5    4.83055696e+00    6.12434611e+00    8.67182283e+00   |   4.83055696e+00    6.12434611e+00    8.67182283e+00   
  6   -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   |  -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   
  7   -2.06502695e+00    8.45297254e+00   -8.84652061e+00   |  -2.06502695e+00    8.45297254e+00   -8.84652061e+00   
  8    2.97905391e+01   -9.90210044e+00    3.25396055e+01   |   2.97905391e+01   -9.90210044e+00    3.25396055e+01   
  9    4.83055696e+00    6.12434611e+00    8.67182283e+00   |   4.83055696e+00    6.12434611e+00    8.67182283e+00   
 10   -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   |  -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   
 11   -2.06502695e+00    8.45297254e+00   -8.84652061e+00   |  -2.06502695e+00    8.45297254e+00   -8.84652061e+00   
 12    2.97905391e+01   -9.90210044e+00    3.25396055e+01   |   2.97905391e+01   -9.90210044e+00    3.25396055e+01   
 13    4.83055696e+00    6.12434611e+00    8.67182283e+00   |   4.83055696e+00    6.12434611e+00    8.67182283e+00   
 14   -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   |  -3.25560691e+01   -4.67521821e+00   -3.23649077e+01   
 15   -2.06502695e+00    8.45297254e+00   -8.84652061e+00   |  -2.06502695e+00    8.45297254e+00   -8.84652061e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = TFF   (Configuration in file "config-Ni-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 2.902664398458464
2^p V(r_1,...,r_N)    = 2.902664398458473

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -5.83867647e+00   -9.69148905e+00   -1.14272366e+01   |  -5.83867647e+00   -9.69148905e+00   -1.14272366e+01   
  1    3.59487117e+00    1.33100743e+01   -1.17340640e+01   |   3.59487117e+00    1.33100743e+01   -1.17340640e+01   
  2    5.73657794e+00   -1.25260034e+01    1.44485646e+01   |   5.73657794e+00   -1.25260034e+01    1.44485646e+01   
  3   -3.49277264e+00    8.90741811e+00    8.71273602e+00   |  -3.49277264e+00    8.90741811e+00    8.71273602e+00   
  4   -5.83867647e+00   -9.69148905e+00   -1.14272366e+01   |  -5.83867647e+00   -9.69148905e+00   -1.14272366e+01   
  5    3.59487117e+00    1.33100743e+01   -1.17340640e+01   |   3.59487117e+00    1.33100743e+01   -1.17340640e+01   
  6    5.73657794e+00   -1.25260034e+01    1.44485646e+01   |   5.73657794e+00   -1.25260034e+01    1.44485646e+01   
  7   -3.49277264e+00    8.90741811e+00    8.71273602e+00   |  -3.49277264e+00    8.90741811e+00    8.71273602e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = FTT   (Configuration in file "config-Ni-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -5.593222339159617
2^p V(r_1,...,r_N)    = -5.593222339159672

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   |  -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   
  1    1.18131068e+01   -1.56499009e+00   -4.83662574e+00   |   1.18131068e+01   -1.56499009e+00   -4.83662574e+00   
  2    1.09719576e+01    2.84409617e+00    2.28575664e+00   |   1.09719576e+01    2.84409617e+00    2.28575664e+00   
  3   -1.23625717e+01    2.66248263e+00    7.46541185e+00   |  -1.23625717e+01    2.66248263e+00    7.46541185e+00   
  4   -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   |  -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   
  5    1.18131068e+01   -1.56499009e+00   -4.83662574e+00   |   1.18131068e+01   -1.56499009e+00   -4.83662574e+00   
  6    1.09719576e+01    2.84409617e+00    2.28575664e+00   |   1.09719576e+01    2.84409617e+00    2.28575664e+00   
  7   -1.23625717e+01    2.66248263e+00    7.46541185e+00   |  -1.23625717e+01    2.66248263e+00    7.46541185e+00   
  8   -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   |  -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   
  9    1.18131068e+01   -1.56499009e+00   -4.83662574e+00   |   1.18131068e+01   -1.56499009e+00   -4.83662574e+00   
 10    1.09719576e+01    2.84409617e+00    2.28575664e+00   |   1.09719576e+01    2.84409617e+00    2.28575664e+00   
 11   -1.23625717e+01    2.66248263e+00    7.46541185e+00   |  -1.23625717e+01    2.66248263e+00    7.46541185e+00   
 12   -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   |  -1.04224926e+01   -3.94158872e+00   -4.91454275e+00   
 13    1.18131068e+01   -1.56499009e+00   -4.83662574e+00   |   1.18131068e+01   -1.56499009e+00   -4.83662574e+00   
 14    1.09719576e+01    2.84409617e+00    2.28575664e+00   |   1.09719576e+01    2.84409617e+00    2.28575664e+00   
 15   -1.23625717e+01    2.66248263e+00    7.46541185e+00   |  -1.23625717e+01    2.66248263e+00    7.46541185e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = FTF   (Configuration in file "config-Ni-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 1.408139200667213
2^p V(r_1,...,r_N)    = 1.4081392006672242

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.16073108e+01   -3.60783808e+00   -8.32280181e+00   |  -1.16073108e+01   -3.60783808e+00   -8.32280181e+00   
  1    8.64206913e+00    4.89727035e+00   -1.04552559e+01   |   8.64206913e+00    4.89727035e+00   -1.04552559e+01   
  2    1.09621804e+01   -2.29363928e+00    9.44867697e+00   |   1.09621804e+01   -2.29363928e+00    9.44867697e+00   
  3   -7.99693866e+00    1.00420702e+00    9.32938072e+00   |  -7.99693866e+00    1.00420702e+00    9.32938072e+00   
  4   -1.16073108e+01   -3.60783808e+00   -8.32280181e+00   |  -1.16073108e+01   -3.60783808e+00   -8.32280181e+00   
  5    8.64206913e+00    4.89727035e+00   -1.04552559e+01   |   8.64206913e+00    4.89727035e+00   -1.04552559e+01   
  6    1.09621804e+01   -2.29363928e+00    9.44867697e+00   |   1.09621804e+01   -2.29363928e+00    9.44867697e+00   
  7   -7.99693866e+00    1.00420702e+00    9.32938072e+00   |  -7.99693866e+00    1.00420702e+00    9.32938072e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MONOATOMIC STRUCTURE -- Species = Ni, PBC = FFT   (Configuration in file "config-Ni-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -9.10321356527961
2^p V(r_1,...,r_N)    = -9.103213565279598

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -6.90746074e+00   -6.81772929e+00   -1.06124145e-01   |  -6.90746074e+00   -6.81772929e+00   -1.06124145e-01   
  1    6.57440285e+00    7.15399261e+00   -1.55702154e+00   |   6.57440285e+00    7.15399261e+00   -1.55702154e+00   
  2    4.89920411e+00   -6.57252676e+00   -1.33447978e+00   |   4.89920411e+00   -6.57252676e+00   -1.33447978e+00   
  3   -4.56614622e+00    6.23626345e+00    2.99762546e+00   |  -4.56614622e+00    6.23626345e+00    2.99762546e+00   
  4   -6.90746074e+00   -6.81772929e+00   -1.06124145e-01   |  -6.90746074e+00   -6.81772929e+00   -1.06124145e-01   
  5    6.57440285e+00    7.15399261e+00   -1.55702154e+00   |   6.57440285e+00    7.15399261e+00   -1.55702154e+00   
  6    4.89920411e+00   -6.57252676e+00   -1.33447978e+00   |   4.89920411e+00   -6.57252676e+00   -1.33447978e+00   
  7   -4.56614622e+00    6.23626345e+00    2.99762546e+00   |  -4.56614622e+00    6.23626345e+00    2.99762546e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = TTT   (Configuration in file "config-CoCrCuFeNi-TTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=3 periodic directions, which means an increase by a factor n=2^3=8
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -235.4895231145984
2^p V(r_1,...,r_N)    = -235.48952311461144

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
  1   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
  2   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
  3    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
  4    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
  5    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
  6    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
  7    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
  8    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
  9    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
 10   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
 11    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
 12    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
 13   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
 14   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
 15    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
 16    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
 17   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
 18    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
 19   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
 20   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
 21   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
 22   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
 23    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
 24    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
 25   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
 26   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
 27    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
 28    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
 29   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
 30   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
 31   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
 32   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
 33   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
 34   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
 35    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
 36    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
 37    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
 38    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
 39    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
 40    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
 41    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
 42   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
 43    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
 44    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
 45   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
 46   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
 47    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
 48    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
 49   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
 50    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
 51   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
 52   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
 53   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
 54   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
 55    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
 56    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
 57   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
 58   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
 59    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
 60    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
 61   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
 62   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
 63   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
 64   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
 65   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
 66   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
 67    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
 68    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
 69    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
 70    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
 71    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
 72    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
 73    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
 74   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
 75    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
 76    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
 77   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
 78   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
 79    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
 80    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
 81   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
 82    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
 83   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
 84   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
 85   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
 86   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
 87    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
 88    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
 89   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
 90   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
 91    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
 92    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
 93   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
 94   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
 95   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
 96   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
 97   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
 98   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
 99    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
100    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
101    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
102    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
103    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
104    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
105    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
106   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
107    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
108    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
109   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
110   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
111    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
112    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
113   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
114    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
115   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
116   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
117   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
118   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
119    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
120    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
121   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
122   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
123    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
124    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
125   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
126   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
127   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
128   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
129   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
130   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
131    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
132    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
133    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
134    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
135    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
136    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
137    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
138   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
139    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
140    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
141   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
142   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
143    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
144    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
145   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
146    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
147   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
148   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
149   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
150   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
151    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
152    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
153   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
154   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
155    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
156    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
157   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
158   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
159   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
160   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
161   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
162   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
163    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
164    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
165    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
166    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
167    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
168    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
169    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
170   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
171    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
172    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
173   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
174   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
175    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
176    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
177   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
178    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
179   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
180   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
181   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
182   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
183    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
184    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
185   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
186   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
187    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
188    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
189   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
190   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
191   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
192   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
193   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
194   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
195    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
196    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
197    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
198    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
199    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
200    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
201    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
202   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
203    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
204    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
205   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
206   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
207    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
208    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
209   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
210    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
211   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
212   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
213   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
214   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
215    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
216    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
217   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
218   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
219    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
220    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
221   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
222   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
223   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
224   -5.78451296e+00   -9.93226715e-02    1.09894356e+01   |  -5.78451296e+00   -9.93226715e-02    1.09894356e+01   
225   -2.39113322e+00    6.03442839e+00    6.56749734e+00   |  -2.39113322e+00    6.03442839e+00    6.56749734e+00   
226   -1.35486406e+01   -3.56220529e+00    1.12129814e+01   |  -1.35486406e+01   -3.56220529e+00    1.12129814e+01   
227    2.93372123e+00   -7.57691963e+00   -3.72267694e+00   |   2.93372123e+00   -7.57691963e+00   -3.72267694e+00   
228    8.34350218e+00   -3.31966441e+00   -5.06401395e+00   |   8.34350218e+00   -3.31966441e+00   -5.06401395e+00   
229    2.26677065e+00   -4.28273480e-01    2.12760436e+00   |   2.26677065e+00   -4.28273480e-01    2.12760436e+00   
230    7.39805776e+00   -2.78699064e+00   -3.38006852e+00   |   7.39805776e+00   -2.78699064e+00   -3.38006852e+00   
231    7.17536158e+00   -1.70849423e+00   -3.28911394e+00   |   7.17536158e+00   -1.70849423e+00   -3.28911394e+00   
232    6.14272054e+00    1.30211342e+00    3.05024034e+00   |   6.14272054e+00    1.30211342e+00    3.05024034e+00   
233    1.98538433e+00   -4.58374572e+00   -4.41265206e+00   |   1.98538433e+00   -4.58374572e+00   -4.41265206e+00   
234   -1.03637286e+01    3.09595701e+00   -2.62503694e+00   |  -1.03637286e+01    3.09595701e+00   -2.62503694e+00   
235    6.23361579e+00    1.09063760e+01   -1.70974380e+01   |   6.23361579e+00    1.09063760e+01   -1.70974380e+01   
236    3.08434785e+00    4.81258236e+00   -6.11413006e+00   |   3.08434785e+00    4.81258236e+00   -6.11413006e+00   
237   -4.05680548e+00   -2.59419331e+00    1.40022765e+01   |  -4.05680548e+00   -2.59419331e+00    1.40022765e+01   
238   -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   |  -2.19616412e+00   -2.92286820e-01   -7.03643272e+00   
239    2.76865292e+00    3.61548158e+00   -4.00407522e+00   |   2.76865292e+00    3.61548158e+00   -4.00407522e+00   
240    1.00215427e+01    6.38071868e+00   -9.56806966e+00   |   1.00215427e+01    6.38071868e+00   -9.56806966e+00   
241   -7.18355871e+00   -5.11914523e+00    5.31378058e+00   |  -7.18355871e+00   -5.11914523e+00    5.31378058e+00   
242    1.96407013e+01   -2.16837725e+01   -9.34606189e+00   |   1.96407013e+01   -2.16837725e+01   -9.34606189e+00   
243   -1.91085794e+01    2.12157760e+01   -4.67664044e+00   |  -1.91085794e+01    2.12157760e+01   -4.67664044e+00   
244   -2.12773338e+00   -6.10676176e-01    9.86514826e+00   |  -2.12773338e+00   -6.10676176e-01    9.86514826e+00   
245   -3.24912824e-01   -5.22675612e+00    4.63747892e+00   |  -3.24912824e-01   -5.22675612e+00    4.63747892e+00   
246   -2.86643142e+00    7.72450232e+00   -3.26987146e+00   |  -2.86643142e+00    7.72450232e+00   -3.26987146e+00   
247    2.08383936e+00   -1.11812640e+00   -4.20546763e+00   |   2.08383936e+00   -1.11812640e+00   -4.20546763e+00   
248    7.13699897e+00   -9.01428605e+00    1.50305021e+01   |   7.13699897e+00   -9.01428605e+00    1.50305021e+01   
249   -5.05981247e+00    5.36657938e+00   -2.94359388e+00   |  -5.05981247e+00    5.36657938e+00   -2.94359388e+00   
250   -2.87285938e+00    6.06343119e+00    2.88371570e+00   |  -2.87285938e+00    6.06343119e+00    2.88371570e+00   
251    6.37881919e+00   -4.01706125e+00    3.73820411e-01   |   6.37881919e+00   -4.01706125e+00    3.73820411e-01   
252    5.52020977e+00    2.52518556e+00    4.98019809e+00   |   5.52020977e+00    2.52518556e+00    4.98019809e+00   
253   -1.16002688e+01   -3.68007504e+00    1.69559637e+00   |  -1.16002688e+01   -3.68007504e+00    1.69559637e+00   
254   -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   |  -5.48641434e+00   -1.27652408e-01   -4.53717022e+00   
255   -4.14269044e+00   -1.49348451e+00    2.56223751e+00   |  -4.14269044e+00   -1.49348451e+00    2.56223751e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = TTF   (Configuration in file "config-CoCrCuFeNi-TTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -3.408601047421557
2^p V(r_1,...,r_N)    = -3.4086010474219246

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -2.56107952e+01    4.75939929e+00   -2.21465570e+01   |  -2.56107952e+01    4.75939929e+00   -2.21465570e+01   
  1    1.07710564e+01   -2.11899067e+00   -9.58222060e+00   |   1.07710564e+01   -2.11899067e+00   -9.58222060e+00   
  2    1.78566107e+01    6.71497061e+00    2.03275289e+01   |   1.78566107e+01    6.71497061e+00    2.03275289e+01   
  3   -1.03253759e+01    2.59542955e-01    7.46912538e+00   |  -1.03253759e+01    2.59542955e-01    7.46912538e+00   
  4   -2.79368879e+00    4.88335152e+00   -7.89778440e+00   |  -2.79368879e+00    4.88335152e+00   -7.89778440e+00   
  5   -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   |  -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   
  6    9.83862188e+00   -4.62030040e+00   -5.63780875e+00   |   9.83862188e+00   -4.62030040e+00   -5.63780875e+00   
  7   -3.42901511e+00    3.51658329e+00   -1.18817639e+00   |  -3.42901511e+00    3.51658329e+00   -1.18817639e+00   
  8   -1.42232362e+00    5.74273975e+00   -6.75454245e+00   |  -1.42232362e+00    5.74273975e+00   -6.75454245e+00   
  9    6.73569565e+00   -9.91911589e+00   -1.33513960e+01   |   6.73569565e+00   -9.91911589e+00   -1.33513960e+01   
 10   -4.20169761e+00    9.89631779e-01    4.38300654e+00   |  -4.20169761e+00    9.89631779e-01    4.38300654e+00   
 11   -3.09418195e+00   -2.95864068e+00    2.80627065e+00   |  -3.09418195e+00   -2.95864068e+00    2.80627065e+00   
 12   -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   |  -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   
 13    8.71062855e+00    1.24287202e+01   -1.48440908e+01   |   8.71062855e+00    1.24287202e+01   -1.48440908e+01   
 14    3.89090026e+00   -8.82147874e+00    1.73960309e+01   |   3.89090026e+00   -8.82147874e+00    1.73960309e+01   
 15    2.03985584e+00    2.75572564e+00    9.66928916e+00   |   2.03985584e+00    2.75572564e+00    9.66928916e+00   
 16    7.12099704e+00    6.00833800e+00   -5.10179764e+00   |   7.12099704e+00    6.00833800e+00   -5.10179764e+00   
 17    4.26038323e+00   -1.79180109e+00    4.95160288e+00   |   4.26038323e+00   -1.79180109e+00    4.95160288e+00   
 18    3.23672581e+00    4.59832930e+00    2.26933302e+00   |   3.23672581e+00    4.59832930e+00    2.26933302e+00   
 19   -1.52701207e+01   -2.55819558e+01    9.40808735e+00   |  -1.52701207e+01   -2.55819558e+01    9.40808735e+00   
 20   -7.59699717e+00   -2.99164097e+00    6.35727822e+00   |  -7.59699717e+00   -2.99164097e+00    6.35727822e+00   
 21    4.62344919e+00    5.23295539e+00   -3.97346394e+00   |   4.62344919e+00    5.23295539e+00   -3.97346394e+00   
 22   -4.48809552e+00    8.78587512e+00    1.30805181e+01   |  -4.48809552e+00    8.78587512e+00    1.30805181e+01   
 23   -4.83343119e+00   -7.21054312e+00    5.35440144e+00   |  -4.83343119e+00   -7.21054312e+00    5.35440144e+00   
 24   -4.42796054e-01    8.24467826e-01   -8.65820911e+00   |  -4.42796054e-01    8.24467826e-01   -8.65820911e+00   
 25   -3.18017776e+00    1.48936685e+00    3.57349168e+00   |  -3.18017776e+00    1.48936685e+00    3.57349168e+00   
 26    1.80168131e+01    1.97084677e+01    3.06692975e+00   |   1.80168131e+01    1.97084677e+01    3.06692975e+00   
 27    1.48913897e-01   -3.72167537e+00    7.41292911e+00   |   1.48913897e-01   -3.72167537e+00    7.41292911e+00   
 28    2.51161429e-01   -1.17798450e+01   -1.22769250e+01   |   2.51161429e-01   -1.17798450e+01   -1.22769250e+01   
 29   -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   |  -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   
 30    7.26622371e-01    4.12918959e-01    8.47979720e+00   |   7.26622371e-01    4.12918959e-01    8.47979720e+00   
 31   -2.70014441e+00    1.06328124e+01    1.69422615e+01   |  -2.70014441e+00    1.06328124e+01    1.69422615e+01   
 32   -2.56107952e+01    4.75939929e+00   -2.21465570e+01   |  -2.56107952e+01    4.75939929e+00   -2.21465570e+01   
 33    1.07710564e+01   -2.11899067e+00   -9.58222060e+00   |   1.07710564e+01   -2.11899067e+00   -9.58222060e+00   
 34    1.78566107e+01    6.71497061e+00    2.03275289e+01   |   1.78566107e+01    6.71497061e+00    2.03275289e+01   
 35   -1.03253759e+01    2.59542955e-01    7.46912538e+00   |  -1.03253759e+01    2.59542955e-01    7.46912538e+00   
 36   -2.79368879e+00    4.88335152e+00   -7.89778440e+00   |  -2.79368879e+00    4.88335152e+00   -7.89778440e+00   
 37   -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   |  -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   
 38    9.83862188e+00   -4.62030040e+00   -5.63780875e+00   |   9.83862188e+00   -4.62030040e+00   -5.63780875e+00   
 39   -3.42901511e+00    3.51658329e+00   -1.18817639e+00   |  -3.42901511e+00    3.51658329e+00   -1.18817639e+00   
 40   -1.42232362e+00    5.74273975e+00   -6.75454245e+00   |  -1.42232362e+00    5.74273975e+00   -6.75454245e+00   
 41    6.73569565e+00   -9.91911589e+00   -1.33513960e+01   |   6.73569565e+00   -9.91911589e+00   -1.33513960e+01   
 42   -4.20169761e+00    9.89631779e-01    4.38300654e+00   |  -4.20169761e+00    9.89631779e-01    4.38300654e+00   
 43   -3.09418195e+00   -2.95864068e+00    2.80627065e+00   |  -3.09418195e+00   -2.95864068e+00    2.80627065e+00   
 44   -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   |  -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   
 45    8.71062855e+00    1.24287202e+01   -1.48440908e+01   |   8.71062855e+00    1.24287202e+01   -1.48440908e+01   
 46    3.89090026e+00   -8.82147874e+00    1.73960309e+01   |   3.89090026e+00   -8.82147874e+00    1.73960309e+01   
 47    2.03985584e+00    2.75572564e+00    9.66928916e+00   |   2.03985584e+00    2.75572564e+00    9.66928916e+00   
 48    7.12099704e+00    6.00833800e+00   -5.10179764e+00   |   7.12099704e+00    6.00833800e+00   -5.10179764e+00   
 49    4.26038323e+00   -1.79180109e+00    4.95160288e+00   |   4.26038323e+00   -1.79180109e+00    4.95160288e+00   
 50    3.23672581e+00    4.59832930e+00    2.26933302e+00   |   3.23672581e+00    4.59832930e+00    2.26933302e+00   
 51   -1.52701207e+01   -2.55819558e+01    9.40808735e+00   |  -1.52701207e+01   -2.55819558e+01    9.40808735e+00   
 52   -7.59699717e+00   -2.99164097e+00    6.35727822e+00   |  -7.59699717e+00   -2.99164097e+00    6.35727822e+00   
 53    4.62344919e+00    5.23295539e+00   -3.97346394e+00   |   4.62344919e+00    5.23295539e+00   -3.97346394e+00   
 54   -4.48809552e+00    8.78587512e+00    1.30805181e+01   |  -4.48809552e+00    8.78587512e+00    1.30805181e+01   
 55   -4.83343119e+00   -7.21054312e+00    5.35440144e+00   |  -4.83343119e+00   -7.21054312e+00    5.35440144e+00   
 56   -4.42796054e-01    8.24467826e-01   -8.65820911e+00   |  -4.42796054e-01    8.24467826e-01   -8.65820911e+00   
 57   -3.18017776e+00    1.48936685e+00    3.57349168e+00   |  -3.18017776e+00    1.48936685e+00    3.57349168e+00   
 58    1.80168131e+01    1.97084677e+01    3.06692975e+00   |   1.80168131e+01    1.97084677e+01    3.06692975e+00   
 59    1.48913897e-01   -3.72167537e+00    7.41292911e+00   |   1.48913897e-01   -3.72167537e+00    7.41292911e+00   
 60    2.51161429e-01   -1.17798450e+01   -1.22769250e+01   |   2.51161429e-01   -1.17798450e+01   -1.22769250e+01   
 61   -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   |  -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   
 62    7.26622371e-01    4.12918959e-01    8.47979720e+00   |   7.26622371e-01    4.12918959e-01    8.47979720e+00   
 63   -2.70014441e+00    1.06328124e+01    1.69422615e+01   |  -2.70014441e+00    1.06328124e+01    1.69422615e+01   
 64   -2.56107952e+01    4.75939929e+00   -2.21465570e+01   |  -2.56107952e+01    4.75939929e+00   -2.21465570e+01   
 65    1.07710564e+01   -2.11899067e+00   -9.58222060e+00   |   1.07710564e+01   -2.11899067e+00   -9.58222060e+00   
 66    1.78566107e+01    6.71497061e+00    2.03275289e+01   |   1.78566107e+01    6.71497061e+00    2.03275289e+01   
 67   -1.03253759e+01    2.59542955e-01    7.46912538e+00   |  -1.03253759e+01    2.59542955e-01    7.46912538e+00   
 68   -2.79368879e+00    4.88335152e+00   -7.89778440e+00   |  -2.79368879e+00    4.88335152e+00   -7.89778440e+00   
 69   -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   |  -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   
 70    9.83862188e+00   -4.62030040e+00   -5.63780875e+00   |   9.83862188e+00   -4.62030040e+00   -5.63780875e+00   
 71   -3.42901511e+00    3.51658329e+00   -1.18817639e+00   |  -3.42901511e+00    3.51658329e+00   -1.18817639e+00   
 72   -1.42232362e+00    5.74273975e+00   -6.75454245e+00   |  -1.42232362e+00    5.74273975e+00   -6.75454245e+00   
 73    6.73569565e+00   -9.91911589e+00   -1.33513960e+01   |   6.73569565e+00   -9.91911589e+00   -1.33513960e+01   
 74   -4.20169761e+00    9.89631779e-01    4.38300654e+00   |  -4.20169761e+00    9.89631779e-01    4.38300654e+00   
 75   -3.09418195e+00   -2.95864068e+00    2.80627065e+00   |  -3.09418195e+00   -2.95864068e+00    2.80627065e+00   
 76   -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   |  -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   
 77    8.71062855e+00    1.24287202e+01   -1.48440908e+01   |   8.71062855e+00    1.24287202e+01   -1.48440908e+01   
 78    3.89090026e+00   -8.82147874e+00    1.73960309e+01   |   3.89090026e+00   -8.82147874e+00    1.73960309e+01   
 79    2.03985584e+00    2.75572564e+00    9.66928916e+00   |   2.03985584e+00    2.75572564e+00    9.66928916e+00   
 80    7.12099704e+00    6.00833800e+00   -5.10179764e+00   |   7.12099704e+00    6.00833800e+00   -5.10179764e+00   
 81    4.26038323e+00   -1.79180109e+00    4.95160288e+00   |   4.26038323e+00   -1.79180109e+00    4.95160288e+00   
 82    3.23672581e+00    4.59832930e+00    2.26933302e+00   |   3.23672581e+00    4.59832930e+00    2.26933302e+00   
 83   -1.52701207e+01   -2.55819558e+01    9.40808735e+00   |  -1.52701207e+01   -2.55819558e+01    9.40808735e+00   
 84   -7.59699717e+00   -2.99164097e+00    6.35727822e+00   |  -7.59699717e+00   -2.99164097e+00    6.35727822e+00   
 85    4.62344919e+00    5.23295539e+00   -3.97346394e+00   |   4.62344919e+00    5.23295539e+00   -3.97346394e+00   
 86   -4.48809552e+00    8.78587512e+00    1.30805181e+01   |  -4.48809552e+00    8.78587512e+00    1.30805181e+01   
 87   -4.83343119e+00   -7.21054312e+00    5.35440144e+00   |  -4.83343119e+00   -7.21054312e+00    5.35440144e+00   
 88   -4.42796054e-01    8.24467826e-01   -8.65820911e+00   |  -4.42796054e-01    8.24467826e-01   -8.65820911e+00   
 89   -3.18017776e+00    1.48936685e+00    3.57349168e+00   |  -3.18017776e+00    1.48936685e+00    3.57349168e+00   
 90    1.80168131e+01    1.97084677e+01    3.06692975e+00   |   1.80168131e+01    1.97084677e+01    3.06692975e+00   
 91    1.48913897e-01   -3.72167537e+00    7.41292911e+00   |   1.48913897e-01   -3.72167537e+00    7.41292911e+00   
 92    2.51161429e-01   -1.17798450e+01   -1.22769250e+01   |   2.51161429e-01   -1.17798450e+01   -1.22769250e+01   
 93   -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   |  -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   
 94    7.26622371e-01    4.12918959e-01    8.47979720e+00   |   7.26622371e-01    4.12918959e-01    8.47979720e+00   
 95   -2.70014441e+00    1.06328124e+01    1.69422615e+01   |  -2.70014441e+00    1.06328124e+01    1.69422615e+01   
 96   -2.56107952e+01    4.75939929e+00   -2.21465570e+01   |  -2.56107952e+01    4.75939929e+00   -2.21465570e+01   
 97    1.07710564e+01   -2.11899067e+00   -9.58222060e+00   |   1.07710564e+01   -2.11899067e+00   -9.58222060e+00   
 98    1.78566107e+01    6.71497061e+00    2.03275289e+01   |   1.78566107e+01    6.71497061e+00    2.03275289e+01   
 99   -1.03253759e+01    2.59542955e-01    7.46912538e+00   |  -1.03253759e+01    2.59542955e-01    7.46912538e+00   
100   -2.79368879e+00    4.88335152e+00   -7.89778440e+00   |  -2.79368879e+00    4.88335152e+00   -7.89778440e+00   
101   -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   |  -1.02110672e+00   -4.70710267e+00   -7.08985448e+00   
102    9.83862188e+00   -4.62030040e+00   -5.63780875e+00   |   9.83862188e+00   -4.62030040e+00   -5.63780875e+00   
103   -3.42901511e+00    3.51658329e+00   -1.18817639e+00   |  -3.42901511e+00    3.51658329e+00   -1.18817639e+00   
104   -1.42232362e+00    5.74273975e+00   -6.75454245e+00   |  -1.42232362e+00    5.74273975e+00   -6.75454245e+00   
105    6.73569565e+00   -9.91911589e+00   -1.33513960e+01   |   6.73569565e+00   -9.91911589e+00   -1.33513960e+01   
106   -4.20169761e+00    9.89631779e-01    4.38300654e+00   |  -4.20169761e+00    9.89631779e-01    4.38300654e+00   
107   -3.09418195e+00   -2.95864068e+00    2.80627065e+00   |  -3.09418195e+00   -2.95864068e+00    2.80627065e+00   
108   -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   |  -5.62103304e+00   -8.42297051e+00   -1.44733780e+01   
109    8.71062855e+00    1.24287202e+01   -1.48440908e+01   |   8.71062855e+00    1.24287202e+01   -1.48440908e+01   
110    3.89090026e+00   -8.82147874e+00    1.73960309e+01   |   3.89090026e+00   -8.82147874e+00    1.73960309e+01   
111    2.03985584e+00    2.75572564e+00    9.66928916e+00   |   2.03985584e+00    2.75572564e+00    9.66928916e+00   
112    7.12099704e+00    6.00833800e+00   -5.10179764e+00   |   7.12099704e+00    6.00833800e+00   -5.10179764e+00   
113    4.26038323e+00   -1.79180109e+00    4.95160288e+00   |   4.26038323e+00   -1.79180109e+00    4.95160288e+00   
114    3.23672581e+00    4.59832930e+00    2.26933302e+00   |   3.23672581e+00    4.59832930e+00    2.26933302e+00   
115   -1.52701207e+01   -2.55819558e+01    9.40808735e+00   |  -1.52701207e+01   -2.55819558e+01    9.40808735e+00   
116   -7.59699717e+00   -2.99164097e+00    6.35727822e+00   |  -7.59699717e+00   -2.99164097e+00    6.35727822e+00   
117    4.62344919e+00    5.23295539e+00   -3.97346394e+00   |   4.62344919e+00    5.23295539e+00   -3.97346394e+00   
118   -4.48809552e+00    8.78587512e+00    1.30805181e+01   |  -4.48809552e+00    8.78587512e+00    1.30805181e+01   
119   -4.83343119e+00   -7.21054312e+00    5.35440144e+00   |  -4.83343119e+00   -7.21054312e+00    5.35440144e+00   
120   -4.42796054e-01    8.24467826e-01   -8.65820911e+00   |  -4.42796054e-01    8.24467826e-01   -8.65820911e+00   
121   -3.18017776e+00    1.48936685e+00    3.57349168e+00   |  -3.18017776e+00    1.48936685e+00    3.57349168e+00   
122    1.80168131e+01    1.97084677e+01    3.06692975e+00   |   1.80168131e+01    1.97084677e+01    3.06692975e+00   
123    1.48913897e-01   -3.72167537e+00    7.41292911e+00   |   1.48913897e-01   -3.72167537e+00    7.41292911e+00   
124    2.51161429e-01   -1.17798450e+01   -1.22769250e+01   |   2.51161429e-01   -1.17798450e+01   -1.22769250e+01   
125   -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   |  -2.19745455e+00   -5.09813561e+00   -9.97167730e+00   
126    7.26622371e-01    4.12918959e-01    8.47979720e+00   |   7.26622371e-01    4.12918959e-01    8.47979720e+00   
127   -2.70014441e+00    1.06328124e+01    1.69422615e+01   |  -2.70014441e+00    1.06328124e+01    1.69422615e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = TFT   (Configuration in file "config-CoCrCuFeNi-TFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -1.36657455568737
2^p V(r_1,...,r_N)    = -1.366574555689323

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   |  -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   
  1   -4.40089832e+00    9.12492498e+00   -9.41894311e+00   |  -4.40089832e+00    9.12492498e+00   -9.41894311e+00   
  2    2.90883796e+00   -8.98888930e+00    1.11955237e+01   |   2.90883796e+00   -8.98888930e+00    1.11955237e+01   
  3    3.41962207e+00    3.48364424e+00    7.52946231e+00   |   3.41962207e+00    3.48364424e+00    7.52946231e+00   
  4    2.08236885e+00   -9.52107449e+00   -2.83794565e+00   |   2.08236885e+00   -9.52107449e+00   -2.83794565e+00   
  5   -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   |  -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   
  6    4.37133164e+00   -7.29152375e+00   -8.85514332e+00   |   4.37133164e+00   -7.29152375e+00   -8.85514332e+00   
  7   -5.52184811e+00   -7.41666619e+00    1.83948019e+01   |  -5.52184811e+00   -7.41666619e+00    1.83948019e+01   
  8    1.04853027e+01    4.15343734e+00   -4.52267344e+00   |   1.04853027e+01    4.15343734e+00   -4.52267344e+00   
  9    4.21725791e+00    1.71534009e+00    2.68535224e+00   |   4.21725791e+00    1.71534009e+00    2.68535224e+00   
 10    3.74208656e+00   -3.53336976e-01   -4.49589877e+00   |   3.74208656e+00   -3.53336976e-01   -4.49589877e+00   
 11   -5.80407534e-01    8.88474213e+00   -8.13424979e+00   |  -5.80407534e-01    8.88474213e+00   -8.13424979e+00   
 12   -7.59063860e+00    1.25558433e+01   -1.34853065e+01   |  -7.59063860e+00    1.25558433e+01   -1.34853065e+01   
 13    1.88609030e+01    1.00676398e+01   -2.94276612e+01   |   1.88609030e+01    1.00676398e+01   -2.94276612e+01   
 14   -5.52553892e+00    3.50221772e+00    1.50934105e+01   |  -5.52553892e+00    3.50221772e+00    1.50934105e+01   
 15   -1.89001285e+01    3.16733216e+00    3.23563380e+01   |  -1.89001285e+01    3.16733216e+00    3.23563380e+01   
 16    3.92464788e+00   -6.04902047e+00   -1.16022953e-01   |   3.92464788e+00   -6.04902047e+00   -1.16022953e-01   
 17    9.92574760e+00   -2.60659047e+01   -2.80672542e+01   |   9.92574760e+00   -2.60659047e+01   -2.80672542e+01   
 18   -2.16559368e+00   -6.59170510e+00    4.12562175e+00   |  -2.16559368e+00   -6.59170510e+00    4.12562175e+00   
 19   -7.75677394e+00   -1.29886790e+01    4.75132229e+00   |  -7.75677394e+00   -1.29886790e+01    4.75132229e+00   
 20   -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   |  -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   
 21    3.16898102e+00    1.00903262e+01   -1.49047698e+00   |   3.16898102e+00    1.00903262e+01   -1.49047698e+00   
 22    4.41303188e+00   -6.65298753e+00    7.24013812e+00   |   4.41303188e+00   -6.65298753e+00    7.24013812e+00   
 23   -2.31208731e+00    4.07977071e+00    4.03534206e-01   |  -2.31208731e+00    4.07977071e+00    4.03534206e-01   
 24    9.92084226e+00   -1.38132409e+01   -4.34805626e+00   |   9.92084226e+00   -1.38132409e+01   -4.34805626e+00   
 25   -6.24876223e-02    5.64320054e+00    1.27373406e+00   |  -6.24876223e-02    5.64320054e+00    1.27373406e+00   
 26    9.83444673e+00    3.24555106e+01    2.15719849e+01   |   9.83444673e+00    3.24555106e+01    2.15719849e+01   
 27    3.68374565e+00    9.38731280e+00    3.12224579e+00   |   3.68374565e+00    9.38731280e+00    3.12224579e+00   
 28   -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   |  -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   
 29   -1.06361832e+01    1.69368473e+01   -2.34644275e+00   |  -1.06361832e+01    1.69368473e+01   -2.34644275e+00   
 30    4.06923978e+00   -6.09120793e+00    9.88018233e+00   |   4.06923978e+00   -6.09120793e+00    9.88018233e+00   
 31   -7.65129960e+00    4.94357963e+00    6.08066445e+00   |  -7.65129960e+00    4.94357963e+00    6.08066445e+00   
 32   -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   |  -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   
 33   -4.40089832e+00    9.12492498e+00   -9.41894311e+00   |  -4.40089832e+00    9.12492498e+00   -9.41894311e+00   
 34    2.90883796e+00   -8.98888930e+00    1.11955237e+01   |   2.90883796e+00   -8.98888930e+00    1.11955237e+01   
 35    3.41962207e+00    3.48364424e+00    7.52946231e+00   |   3.41962207e+00    3.48364424e+00    7.52946231e+00   
 36    2.08236885e+00   -9.52107449e+00   -2.83794565e+00   |   2.08236885e+00   -9.52107449e+00   -2.83794565e+00   
 37   -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   |  -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   
 38    4.37133164e+00   -7.29152375e+00   -8.85514332e+00   |   4.37133164e+00   -7.29152375e+00   -8.85514332e+00   
 39   -5.52184811e+00   -7.41666619e+00    1.83948019e+01   |  -5.52184811e+00   -7.41666619e+00    1.83948019e+01   
 40    1.04853027e+01    4.15343734e+00   -4.52267344e+00   |   1.04853027e+01    4.15343734e+00   -4.52267344e+00   
 41    4.21725791e+00    1.71534009e+00    2.68535224e+00   |   4.21725791e+00    1.71534009e+00    2.68535224e+00   
 42    3.74208656e+00   -3.53336976e-01   -4.49589877e+00   |   3.74208656e+00   -3.53336976e-01   -4.49589877e+00   
 43   -5.80407534e-01    8.88474213e+00   -8.13424979e+00   |  -5.80407534e-01    8.88474213e+00   -8.13424979e+00   
 44   -7.59063860e+00    1.25558433e+01   -1.34853065e+01   |  -7.59063860e+00    1.25558433e+01   -1.34853065e+01   
 45    1.88609030e+01    1.00676398e+01   -2.94276612e+01   |   1.88609030e+01    1.00676398e+01   -2.94276612e+01   
 46   -5.52553892e+00    3.50221772e+00    1.50934105e+01   |  -5.52553892e+00    3.50221772e+00    1.50934105e+01   
 47   -1.89001285e+01    3.16733216e+00    3.23563380e+01   |  -1.89001285e+01    3.16733216e+00    3.23563380e+01   
 48    3.92464788e+00   -6.04902047e+00   -1.16022953e-01   |   3.92464788e+00   -6.04902047e+00   -1.16022953e-01   
 49    9.92574760e+00   -2.60659047e+01   -2.80672542e+01   |   9.92574760e+00   -2.60659047e+01   -2.80672542e+01   
 50   -2.16559368e+00   -6.59170510e+00    4.12562175e+00   |  -2.16559368e+00   -6.59170510e+00    4.12562175e+00   
 51   -7.75677394e+00   -1.29886790e+01    4.75132229e+00   |  -7.75677394e+00   -1.29886790e+01    4.75132229e+00   
 52   -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   |  -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   
 53    3.16898102e+00    1.00903262e+01   -1.49047698e+00   |   3.16898102e+00    1.00903262e+01   -1.49047698e+00   
 54    4.41303188e+00   -6.65298753e+00    7.24013812e+00   |   4.41303188e+00   -6.65298753e+00    7.24013812e+00   
 55   -2.31208731e+00    4.07977071e+00    4.03534206e-01   |  -2.31208731e+00    4.07977071e+00    4.03534206e-01   
 56    9.92084226e+00   -1.38132409e+01   -4.34805626e+00   |   9.92084226e+00   -1.38132409e+01   -4.34805626e+00   
 57   -6.24876223e-02    5.64320054e+00    1.27373406e+00   |  -6.24876223e-02    5.64320054e+00    1.27373406e+00   
 58    9.83444673e+00    3.24555106e+01    2.15719849e+01   |   9.83444673e+00    3.24555106e+01    2.15719849e+01   
 59    3.68374565e+00    9.38731280e+00    3.12224579e+00   |   3.68374565e+00    9.38731280e+00    3.12224579e+00   
 60   -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   |  -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   
 61   -1.06361832e+01    1.69368473e+01   -2.34644275e+00   |  -1.06361832e+01    1.69368473e+01   -2.34644275e+00   
 62    4.06923978e+00   -6.09120793e+00    9.88018233e+00   |   4.06923978e+00   -6.09120793e+00    9.88018233e+00   
 63   -7.65129960e+00    4.94357963e+00    6.08066445e+00   |  -7.65129960e+00    4.94357963e+00    6.08066445e+00   
 64   -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   |  -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   
 65   -4.40089832e+00    9.12492498e+00   -9.41894311e+00   |  -4.40089832e+00    9.12492498e+00   -9.41894311e+00   
 66    2.90883796e+00   -8.98888930e+00    1.11955237e+01   |   2.90883796e+00   -8.98888930e+00    1.11955237e+01   
 67    3.41962207e+00    3.48364424e+00    7.52946231e+00   |   3.41962207e+00    3.48364424e+00    7.52946231e+00   
 68    2.08236885e+00   -9.52107449e+00   -2.83794565e+00   |   2.08236885e+00   -9.52107449e+00   -2.83794565e+00   
 69   -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   |  -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   
 70    4.37133164e+00   -7.29152375e+00   -8.85514332e+00   |   4.37133164e+00   -7.29152375e+00   -8.85514332e+00   
 71   -5.52184811e+00   -7.41666619e+00    1.83948019e+01   |  -5.52184811e+00   -7.41666619e+00    1.83948019e+01   
 72    1.04853027e+01    4.15343734e+00   -4.52267344e+00   |   1.04853027e+01    4.15343734e+00   -4.52267344e+00   
 73    4.21725791e+00    1.71534009e+00    2.68535224e+00   |   4.21725791e+00    1.71534009e+00    2.68535224e+00   
 74    3.74208656e+00   -3.53336976e-01   -4.49589877e+00   |   3.74208656e+00   -3.53336976e-01   -4.49589877e+00   
 75   -5.80407534e-01    8.88474213e+00   -8.13424979e+00   |  -5.80407534e-01    8.88474213e+00   -8.13424979e+00   
 76   -7.59063860e+00    1.25558433e+01   -1.34853065e+01   |  -7.59063860e+00    1.25558433e+01   -1.34853065e+01   
 77    1.88609030e+01    1.00676398e+01   -2.94276612e+01   |   1.88609030e+01    1.00676398e+01   -2.94276612e+01   
 78   -5.52553892e+00    3.50221772e+00    1.50934105e+01   |  -5.52553892e+00    3.50221772e+00    1.50934105e+01   
 79   -1.89001285e+01    3.16733216e+00    3.23563380e+01   |  -1.89001285e+01    3.16733216e+00    3.23563380e+01   
 80    3.92464788e+00   -6.04902047e+00   -1.16022953e-01   |   3.92464788e+00   -6.04902047e+00   -1.16022953e-01   
 81    9.92574760e+00   -2.60659047e+01   -2.80672542e+01   |   9.92574760e+00   -2.60659047e+01   -2.80672542e+01   
 82   -2.16559368e+00   -6.59170510e+00    4.12562175e+00   |  -2.16559368e+00   -6.59170510e+00    4.12562175e+00   
 83   -7.75677394e+00   -1.29886790e+01    4.75132229e+00   |  -7.75677394e+00   -1.29886790e+01    4.75132229e+00   
 84   -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   |  -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   
 85    3.16898102e+00    1.00903262e+01   -1.49047698e+00   |   3.16898102e+00    1.00903262e+01   -1.49047698e+00   
 86    4.41303188e+00   -6.65298753e+00    7.24013812e+00   |   4.41303188e+00   -6.65298753e+00    7.24013812e+00   
 87   -2.31208731e+00    4.07977071e+00    4.03534206e-01   |  -2.31208731e+00    4.07977071e+00    4.03534206e-01   
 88    9.92084226e+00   -1.38132409e+01   -4.34805626e+00   |   9.92084226e+00   -1.38132409e+01   -4.34805626e+00   
 89   -6.24876223e-02    5.64320054e+00    1.27373406e+00   |  -6.24876223e-02    5.64320054e+00    1.27373406e+00   
 90    9.83444673e+00    3.24555106e+01    2.15719849e+01   |   9.83444673e+00    3.24555106e+01    2.15719849e+01   
 91    3.68374565e+00    9.38731280e+00    3.12224579e+00   |   3.68374565e+00    9.38731280e+00    3.12224579e+00   
 92   -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   |  -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   
 93   -1.06361832e+01    1.69368473e+01   -2.34644275e+00   |  -1.06361832e+01    1.69368473e+01   -2.34644275e+00   
 94    4.06923978e+00   -6.09120793e+00    9.88018233e+00   |   4.06923978e+00   -6.09120793e+00    9.88018233e+00   
 95   -7.65129960e+00    4.94357963e+00    6.08066445e+00   |  -7.65129960e+00    4.94357963e+00    6.08066445e+00   
 96   -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   |  -4.58783125e+00   -9.84278880e+00   -5.90126615e+00   
 97   -4.40089832e+00    9.12492498e+00   -9.41894311e+00   |  -4.40089832e+00    9.12492498e+00   -9.41894311e+00   
 98    2.90883796e+00   -8.98888930e+00    1.11955237e+01   |   2.90883796e+00   -8.98888930e+00    1.11955237e+01   
 99    3.41962207e+00    3.48364424e+00    7.52946231e+00   |   3.41962207e+00    3.48364424e+00    7.52946231e+00   
100    2.08236885e+00   -9.52107449e+00   -2.83794565e+00   |   2.08236885e+00   -9.52107449e+00   -2.83794565e+00   
101   -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   |  -1.22105986e+00   -8.21083485e+00   -5.40047685e+00   
102    4.37133164e+00   -7.29152375e+00   -8.85514332e+00   |   4.37133164e+00   -7.29152375e+00   -8.85514332e+00   
103   -5.52184811e+00   -7.41666619e+00    1.83948019e+01   |  -5.52184811e+00   -7.41666619e+00    1.83948019e+01   
104    1.04853027e+01    4.15343734e+00   -4.52267344e+00   |   1.04853027e+01    4.15343734e+00   -4.52267344e+00   
105    4.21725791e+00    1.71534009e+00    2.68535224e+00   |   4.21725791e+00    1.71534009e+00    2.68535224e+00   
106    3.74208656e+00   -3.53336976e-01   -4.49589877e+00   |   3.74208656e+00   -3.53336976e-01   -4.49589877e+00   
107   -5.80407534e-01    8.88474213e+00   -8.13424979e+00   |  -5.80407534e-01    8.88474213e+00   -8.13424979e+00   
108   -7.59063860e+00    1.25558433e+01   -1.34853065e+01   |  -7.59063860e+00    1.25558433e+01   -1.34853065e+01   
109    1.88609030e+01    1.00676398e+01   -2.94276612e+01   |   1.88609030e+01    1.00676398e+01   -2.94276612e+01   
110   -5.52553892e+00    3.50221772e+00    1.50934105e+01   |  -5.52553892e+00    3.50221772e+00    1.50934105e+01   
111   -1.89001285e+01    3.16733216e+00    3.23563380e+01   |  -1.89001285e+01    3.16733216e+00    3.23563380e+01   
112    3.92464788e+00   -6.04902047e+00   -1.16022953e-01   |   3.92464788e+00   -6.04902047e+00   -1.16022953e-01   
113    9.92574760e+00   -2.60659047e+01   -2.80672542e+01   |   9.92574760e+00   -2.60659047e+01   -2.80672542e+01   
114   -2.16559368e+00   -6.59170510e+00    4.12562175e+00   |  -2.16559368e+00   -6.59170510e+00    4.12562175e+00   
115   -7.75677394e+00   -1.29886790e+01    4.75132229e+00   |  -7.75677394e+00   -1.29886790e+01    4.75132229e+00   
116   -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   |  -1.08045907e+01   -6.53794005e+00   -1.42292949e+00   
117    3.16898102e+00    1.00903262e+01   -1.49047698e+00   |   3.16898102e+00    1.00903262e+01   -1.49047698e+00   
118    4.41303188e+00   -6.65298753e+00    7.24013812e+00   |   4.41303188e+00   -6.65298753e+00    7.24013812e+00   
119   -2.31208731e+00    4.07977071e+00    4.03534206e-01   |  -2.31208731e+00    4.07977071e+00    4.03534206e-01   
120    9.92084226e+00   -1.38132409e+01   -4.34805626e+00   |   9.92084226e+00   -1.38132409e+01   -4.34805626e+00   
121   -6.24876223e-02    5.64320054e+00    1.27373406e+00   |  -6.24876223e-02    5.64320054e+00    1.27373406e+00   
122    9.83444673e+00    3.24555106e+01    2.15719849e+01   |   9.83444673e+00    3.24555106e+01    2.15719849e+01   
123    3.68374565e+00    9.38731280e+00    3.12224579e+00   |   3.68374565e+00    9.38731280e+00    3.12224579e+00   
124   -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   |  -9.31102628e+00   -3.77586939e+00   -1.54335692e+01   
125   -1.06361832e+01    1.69368473e+01   -2.34644275e+00   |  -1.06361832e+01    1.69368473e+01   -2.34644275e+00   
126    4.06923978e+00   -6.09120793e+00    9.88018233e+00   |   4.06923978e+00   -6.09120793e+00    9.88018233e+00   
127   -7.65129960e+00    4.94357963e+00    6.08066445e+00   |  -7.65129960e+00    4.94357963e+00    6.08066445e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = TFF   (Configuration in file "config-CoCrCuFeNi-TFF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 22.488109776946118
2^p V(r_1,...,r_N)    = 22.488109776945983

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -6.60427423e+00   -6.76107918e+00   -1.11896087e+01   |  -6.60427423e+00   -6.76107918e+00   -1.11896087e+01   
  1   -5.01750072e+00    4.60428777e+00   -8.37972767e+00   |  -5.01750072e+00    4.60428777e+00   -8.37972767e+00   
  2    6.12258055e+00   -8.96790040e+00    3.28838763e+00   |   6.12258055e+00   -8.96790040e+00    3.28838763e+00   
  3    4.44894414e+00    8.88066794e+00    7.89949179e+00   |   4.44894414e+00    8.88066794e+00    7.89949179e+00   
  4   -2.93062940e+00   -1.14129418e+01   -9.05976147e+00   |  -2.93062940e+00   -1.14129418e+01   -9.05976147e+00   
  5    4.06323197e+00   -5.19155110e+00   -1.69319067e+01   |   4.06323197e+00   -5.19155110e+00   -1.69319067e+01   
  6    3.12798504e+00   -1.19887070e+01    3.57216542e+00   |   3.12798504e+00   -1.19887070e+01    3.57216542e+00   
  7   -4.27305050e+00    4.26839870e+00    9.94896159e+00   |  -4.27305050e+00    4.26839870e+00    9.94896159e+00   
  8    5.16576754e+00    3.33769313e+00   -7.39579831e+00   |   5.16576754e+00    3.33769313e+00   -7.39579831e+00   
  9    5.92550913e-01    4.62241753e+00   -1.22967291e+01   |   5.92550913e-01    4.62241753e+00   -1.22967291e+01   
 10   -8.62505014e+00   -1.90237309e+01   -9.12795766e+00   |  -8.62505014e+00   -1.90237309e+01   -9.12795766e+00   
 11   -6.93592792e+00    6.18125345e+00    3.49359210e+00   |  -6.93592792e+00    6.18125345e+00    3.49359210e+00   
 12   -1.48866698e+01    6.03937822e+00   -1.95599347e+01   |  -1.48866698e+01    6.03937822e+00   -1.95599347e+01   
 13    1.58703872e+00    4.60840345e+00   -4.61609952e+00   |   1.58703872e+00    4.60840345e+00   -4.61609952e+00   
 14    1.52616808e+01    7.91769014e+00    2.62358622e+01   |   1.52616808e+01    7.91769014e+00    2.62358622e+01   
 15    1.39021129e+01    1.78607620e+01   -4.61708364e-01   |   1.39021129e+01    1.78607620e+01   -4.61708364e-01   
 16   -4.67284520e-01   -1.00725215e+01    6.49900196e-01   |  -4.67284520e-01   -1.00725215e+01    6.49900196e-01   
 17   -1.20597612e+00   -2.30434763e+00   -1.43871889e+00   |  -1.20597612e+00   -2.30434763e+00   -1.43871889e+00   
 18    5.12145501e+00   -6.02431570e+00    5.77716997e+00   |   5.12145501e+00   -6.02431570e+00    5.77716997e+00   
 19    7.22913332e+00    7.97414834e+00    8.02056945e+00   |   7.22913332e+00    7.97414834e+00    8.02056945e+00   
 20   -1.93569350e+00   -9.30688217e+00    1.13796032e+00   |  -1.93569350e+00   -9.30688217e+00    1.13796032e+00   
 21   -1.63008541e+00    9.20972693e+00   -1.26002395e+01   |  -1.63008541e+00    9.20972693e+00   -1.26002395e+01   
 22   -1.19138310e+00   -1.22803836e+01    5.93710064e+00   |  -1.19138310e+00   -1.22803836e+01    5.93710064e+00   
 23   -7.34743617e+00    3.51213744e+00    6.75439128e+00   |  -7.34743617e+00    3.51213744e+00    6.75439128e+00   
 24   -1.06665073e+01   -8.03832180e+00   -6.73966775e+00   |  -1.06665073e+01   -8.03832180e+00   -6.73966775e+00   
 25   -1.50725242e+01    2.42472514e+01    5.74620727e+00   |  -1.50725242e+01    2.42472514e+01    5.74620727e+00   
 26   -1.68760068e+00   -5.01604280e+00    1.57069735e+01   |  -1.68760068e+00   -5.01604280e+00    1.57069735e+01   
 27    4.41425666e+00    9.40080916e+00    6.02939918e+00   |   4.41425666e+00    9.40080916e+00    6.02939918e+00   
 28    2.06109980e+01   -1.79500385e+01    2.35203547e+00   |   2.06109980e+01   -1.79500385e+01    2.35203547e+00   
 29   -9.22785838e-01    2.77345871e+00   -8.00864095e+00   |  -9.22785838e-01    2.77345871e+00   -8.00864095e+00   
 30   -2.71892406e+00    1.93102072e+00    7.61281836e+00   |  -2.71892406e+00    1.93102072e+00    7.61281836e+00   
 31    2.47156806e+00    6.96925896e+00    7.64351277e+00   |   2.47156806e+00    6.96925896e+00    7.64351277e+00   
 32   -6.60427423e+00   -6.76107918e+00   -1.11896087e+01   |  -6.60427423e+00   -6.76107918e+00   -1.11896087e+01   
 33   -5.01750072e+00    4.60428777e+00   -8.37972767e+00   |  -5.01750072e+00    4.60428777e+00   -8.37972767e+00   
 34    6.12258055e+00   -8.96790040e+00    3.28838763e+00   |   6.12258055e+00   -8.96790040e+00    3.28838763e+00   
 35    4.44894414e+00    8.88066794e+00    7.89949179e+00   |   4.44894414e+00    8.88066794e+00    7.89949179e+00   
 36   -2.93062940e+00   -1.14129418e+01   -9.05976147e+00   |  -2.93062940e+00   -1.14129418e+01   -9.05976147e+00   
 37    4.06323197e+00   -5.19155110e+00   -1.69319067e+01   |   4.06323197e+00   -5.19155110e+00   -1.69319067e+01   
 38    3.12798504e+00   -1.19887070e+01    3.57216542e+00   |   3.12798504e+00   -1.19887070e+01    3.57216542e+00   
 39   -4.27305050e+00    4.26839870e+00    9.94896159e+00   |  -4.27305050e+00    4.26839870e+00    9.94896159e+00   
 40    5.16576754e+00    3.33769313e+00   -7.39579831e+00   |   5.16576754e+00    3.33769313e+00   -7.39579831e+00   
 41    5.92550913e-01    4.62241753e+00   -1.22967291e+01   |   5.92550913e-01    4.62241753e+00   -1.22967291e+01   
 42   -8.62505014e+00   -1.90237309e+01   -9.12795766e+00   |  -8.62505014e+00   -1.90237309e+01   -9.12795766e+00   
 43   -6.93592792e+00    6.18125345e+00    3.49359210e+00   |  -6.93592792e+00    6.18125345e+00    3.49359210e+00   
 44   -1.48866698e+01    6.03937822e+00   -1.95599347e+01   |  -1.48866698e+01    6.03937822e+00   -1.95599347e+01   
 45    1.58703872e+00    4.60840345e+00   -4.61609952e+00   |   1.58703872e+00    4.60840345e+00   -4.61609952e+00   
 46    1.52616808e+01    7.91769014e+00    2.62358622e+01   |   1.52616808e+01    7.91769014e+00    2.62358622e+01   
 47    1.39021129e+01    1.78607620e+01   -4.61708364e-01   |   1.39021129e+01    1.78607620e+01   -4.61708364e-01   
 48   -4.67284520e-01   -1.00725215e+01    6.49900196e-01   |  -4.67284520e-01   -1.00725215e+01    6.49900196e-01   
 49   -1.20597612e+00   -2.30434763e+00   -1.43871889e+00   |  -1.20597612e+00   -2.30434763e+00   -1.43871889e+00   
 50    5.12145501e+00   -6.02431570e+00    5.77716997e+00   |   5.12145501e+00   -6.02431570e+00    5.77716997e+00   
 51    7.22913332e+00    7.97414834e+00    8.02056945e+00   |   7.22913332e+00    7.97414834e+00    8.02056945e+00   
 52   -1.93569350e+00   -9.30688217e+00    1.13796032e+00   |  -1.93569350e+00   -9.30688217e+00    1.13796032e+00   
 53   -1.63008541e+00    9.20972693e+00   -1.26002395e+01   |  -1.63008541e+00    9.20972693e+00   -1.26002395e+01   
 54   -1.19138310e+00   -1.22803836e+01    5.93710064e+00   |  -1.19138310e+00   -1.22803836e+01    5.93710064e+00   
 55   -7.34743617e+00    3.51213744e+00    6.75439128e+00   |  -7.34743617e+00    3.51213744e+00    6.75439128e+00   
 56   -1.06665073e+01   -8.03832180e+00   -6.73966775e+00   |  -1.06665073e+01   -8.03832180e+00   -6.73966775e+00   
 57   -1.50725242e+01    2.42472514e+01    5.74620727e+00   |  -1.50725242e+01    2.42472514e+01    5.74620727e+00   
 58   -1.68760068e+00   -5.01604280e+00    1.57069735e+01   |  -1.68760068e+00   -5.01604280e+00    1.57069735e+01   
 59    4.41425666e+00    9.40080916e+00    6.02939918e+00   |   4.41425666e+00    9.40080916e+00    6.02939918e+00   
 60    2.06109980e+01   -1.79500385e+01    2.35203547e+00   |   2.06109980e+01   -1.79500385e+01    2.35203547e+00   
 61   -9.22785838e-01    2.77345871e+00   -8.00864095e+00   |  -9.22785838e-01    2.77345871e+00   -8.00864095e+00   
 62   -2.71892406e+00    1.93102072e+00    7.61281836e+00   |  -2.71892406e+00    1.93102072e+00    7.61281836e+00   
 63    2.47156806e+00    6.96925896e+00    7.64351277e+00   |   2.47156806e+00    6.96925896e+00    7.64351277e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = FTT   (Configuration in file "config-CoCrCuFeNi-FTT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=2 periodic directions, which means an increase by a factor n=2^2=4
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = -41.71397504216129
2^p V(r_1,...,r_N)    = -41.7139750421614

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -9.40050316e+00    5.19985655e+00   -3.58912196e+00   |  -9.40050316e+00    5.19985655e+00   -3.58912196e+00   
  1    5.74084207e+00    5.59845945e-01   -4.15851366e+00   |   5.74084207e+00    5.59845945e-01   -4.15851366e+00   
  2    9.45248391e+00   -2.88520175e+00   -1.04632055e+01   |   9.45248391e+00   -2.88520175e+00   -1.04632055e+01   
  3   -1.61041894e+01   -2.93900726e+00    1.98543964e+00   |  -1.61041894e+01   -2.93900726e+00    1.98543964e+00   
  4   -6.33281408e+00   -1.35945667e+01    4.34669238e+00   |  -6.33281408e+00   -1.35945667e+01    4.34669238e+00   
  5    1.71103505e+01    6.62305881e+00   -1.01409191e+00   |   1.71103505e+01    6.62305881e+00   -1.01409191e+00   
  6    5.47027099e+00    6.90884501e+00   -9.51374318e-01   |   5.47027099e+00    6.90884501e+00   -9.51374318e-01   
  7   -5.01432731e+00    2.72441699e-01    9.32289834e+00   |  -5.01432731e+00    2.72441699e-01    9.32289834e+00   
  8   -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   |  -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   
  9    1.13507297e+01   -3.77203366e+00    2.22105341e+00   |   1.13507297e+01   -3.77203366e+00    2.22105341e+00   
 10    9.19815850e+00    8.70254156e+00   -9.21213803e-01   |   9.19815850e+00    8.70254156e+00   -9.21213803e-01   
 11   -8.01803095e+00   -4.45817769e+00    5.57471884e+00   |  -8.01803095e+00   -4.45817769e+00    5.57471884e+00   
 12   -5.86253929e+00    5.83652577e+00   -6.34360165e+00   |  -5.86253929e+00    5.83652577e+00   -6.34360165e+00   
 13    6.06199260e+00   -2.48784919e+00   -5.08606488e+00   |   6.06199260e+00   -2.48784919e+00   -5.08606488e+00   
 14    1.18738835e+01   -3.73319855e+00   -4.38866196e-01   |   1.18738835e+01   -3.73319855e+00   -4.38866196e-01   
 15   -1.56385494e+01    5.79235960e+00   -1.99812910e+00   |  -1.56385494e+01    5.79235960e+00   -1.99812910e+00   
 16   -1.94391676e+01   -4.53538809e+00    4.36588740e+00   |  -1.94391676e+01   -4.53538809e+00    4.36588740e+00   
 17    9.31586770e+00    6.63326617e+00   -9.74173126e-01   |   9.31586770e+00    6.63326617e+00   -9.74173126e-01   
 18   -7.35390030e+00   -5.70406986e+00    2.20955436e+00   |  -7.35390030e+00   -5.70406986e+00    2.20955436e+00   
 19   -1.05651022e+01   -1.54295173e+00    7.24897928e+00   |  -1.05651022e+01   -1.54295173e+00    7.24897928e+00   
 20    1.36032888e+01    5.35391680e+00   -3.59291116e+00   |   1.36032888e+01    5.35391680e+00   -3.59291116e+00   
 21    4.54986724e+00   -7.37219893e+00    2.80877935e+00   |   4.54986724e+00   -7.37219893e+00    2.80877935e+00   
 22    9.49751983e+00   -1.31222356e+00   -8.09792389e+00   |   9.49751983e+00   -1.31222356e+00   -8.09792389e+00   
 23    8.80239867e+00    1.08579982e+01   -7.78201226e+00   |   8.80239867e+00    1.08579982e+01   -7.78201226e+00   
 24   -8.38964489e+00    8.26654738e+00    3.35799212e+00   |  -8.38964489e+00    8.26654738e+00    3.35799212e+00   
 25   -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   |  -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   
 26    3.92330889e+00    7.94576256e+00    1.64830722e+00   |   3.92330889e+00    7.94576256e+00    1.64830722e+00   
 27   -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   |  -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   
 28   -4.73119253e+00    2.74183833e+00    2.95416538e+00   |  -4.73119253e+00    2.74183833e+00    2.95416538e+00   
 29    4.58556057e+00   -8.92741912e-01    8.24098182e+00   |   4.58556057e+00   -8.92741912e-01    8.24098182e+00   
 30    2.46231815e+00    1.50440607e+00    7.82438921e+00   |   2.46231815e+00    1.50440607e+00    7.82438921e+00   
 31    3.70740224e+00   -1.01908010e+01    2.67681517e+00   |   3.70740224e+00   -1.01908010e+01    2.67681517e+00   
 32   -9.40050316e+00    5.19985655e+00   -3.58912196e+00   |  -9.40050316e+00    5.19985655e+00   -3.58912196e+00   
 33    5.74084207e+00    5.59845945e-01   -4.15851366e+00   |   5.74084207e+00    5.59845945e-01   -4.15851366e+00   
 34    9.45248391e+00   -2.88520175e+00   -1.04632055e+01   |   9.45248391e+00   -2.88520175e+00   -1.04632055e+01   
 35   -1.61041894e+01   -2.93900726e+00    1.98543964e+00   |  -1.61041894e+01   -2.93900726e+00    1.98543964e+00   
 36   -6.33281408e+00   -1.35945667e+01    4.34669238e+00   |  -6.33281408e+00   -1.35945667e+01    4.34669238e+00   
 37    1.71103505e+01    6.62305881e+00   -1.01409191e+00   |   1.71103505e+01    6.62305881e+00   -1.01409191e+00   
 38    5.47027099e+00    6.90884501e+00   -9.51374318e-01   |   5.47027099e+00    6.90884501e+00   -9.51374318e-01   
 39   -5.01432731e+00    2.72441699e-01    9.32289834e+00   |  -5.01432731e+00    2.72441699e-01    9.32289834e+00   
 40   -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   |  -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   
 41    1.13507297e+01   -3.77203366e+00    2.22105341e+00   |   1.13507297e+01   -3.77203366e+00    2.22105341e+00   
 42    9.19815850e+00    8.70254156e+00   -9.21213803e-01   |   9.19815850e+00    8.70254156e+00   -9.21213803e-01   
 43   -8.01803095e+00   -4.45817769e+00    5.57471884e+00   |  -8.01803095e+00   -4.45817769e+00    5.57471884e+00   
 44   -5.86253929e+00    5.83652577e+00   -6.34360165e+00   |  -5.86253929e+00    5.83652577e+00   -6.34360165e+00   
 45    6.06199260e+00   -2.48784919e+00   -5.08606488e+00   |   6.06199260e+00   -2.48784919e+00   -5.08606488e+00   
 46    1.18738835e+01   -3.73319855e+00   -4.38866196e-01   |   1.18738835e+01   -3.73319855e+00   -4.38866196e-01   
 47   -1.56385494e+01    5.79235960e+00   -1.99812910e+00   |  -1.56385494e+01    5.79235960e+00   -1.99812910e+00   
 48   -1.94391676e+01   -4.53538809e+00    4.36588740e+00   |  -1.94391676e+01   -4.53538809e+00    4.36588740e+00   
 49    9.31586770e+00    6.63326617e+00   -9.74173126e-01   |   9.31586770e+00    6.63326617e+00   -9.74173126e-01   
 50   -7.35390030e+00   -5.70406986e+00    2.20955436e+00   |  -7.35390030e+00   -5.70406986e+00    2.20955436e+00   
 51   -1.05651022e+01   -1.54295173e+00    7.24897928e+00   |  -1.05651022e+01   -1.54295173e+00    7.24897928e+00   
 52    1.36032888e+01    5.35391680e+00   -3.59291116e+00   |   1.36032888e+01    5.35391680e+00   -3.59291116e+00   
 53    4.54986724e+00   -7.37219893e+00    2.80877935e+00   |   4.54986724e+00   -7.37219893e+00    2.80877935e+00   
 54    9.49751983e+00   -1.31222356e+00   -8.09792389e+00   |   9.49751983e+00   -1.31222356e+00   -8.09792389e+00   
 55    8.80239867e+00    1.08579982e+01   -7.78201226e+00   |   8.80239867e+00    1.08579982e+01   -7.78201226e+00   
 56   -8.38964489e+00    8.26654738e+00    3.35799212e+00   |  -8.38964489e+00    8.26654738e+00    3.35799212e+00   
 57   -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   |  -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   
 58    3.92330889e+00    7.94576256e+00    1.64830722e+00   |   3.92330889e+00    7.94576256e+00    1.64830722e+00   
 59   -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   |  -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   
 60   -4.73119253e+00    2.74183833e+00    2.95416538e+00   |  -4.73119253e+00    2.74183833e+00    2.95416538e+00   
 61    4.58556057e+00   -8.92741912e-01    8.24098182e+00   |   4.58556057e+00   -8.92741912e-01    8.24098182e+00   
 62    2.46231815e+00    1.50440607e+00    7.82438921e+00   |   2.46231815e+00    1.50440607e+00    7.82438921e+00   
 63    3.70740224e+00   -1.01908010e+01    2.67681517e+00   |   3.70740224e+00   -1.01908010e+01    2.67681517e+00   
 64   -9.40050316e+00    5.19985655e+00   -3.58912196e+00   |  -9.40050316e+00    5.19985655e+00   -3.58912196e+00   
 65    5.74084207e+00    5.59845945e-01   -4.15851366e+00   |   5.74084207e+00    5.59845945e-01   -4.15851366e+00   
 66    9.45248391e+00   -2.88520175e+00   -1.04632055e+01   |   9.45248391e+00   -2.88520175e+00   -1.04632055e+01   
 67   -1.61041894e+01   -2.93900726e+00    1.98543964e+00   |  -1.61041894e+01   -2.93900726e+00    1.98543964e+00   
 68   -6.33281408e+00   -1.35945667e+01    4.34669238e+00   |  -6.33281408e+00   -1.35945667e+01    4.34669238e+00   
 69    1.71103505e+01    6.62305881e+00   -1.01409191e+00   |   1.71103505e+01    6.62305881e+00   -1.01409191e+00   
 70    5.47027099e+00    6.90884501e+00   -9.51374318e-01   |   5.47027099e+00    6.90884501e+00   -9.51374318e-01   
 71   -5.01432731e+00    2.72441699e-01    9.32289834e+00   |  -5.01432731e+00    2.72441699e-01    9.32289834e+00   
 72   -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   |  -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   
 73    1.13507297e+01   -3.77203366e+00    2.22105341e+00   |   1.13507297e+01   -3.77203366e+00    2.22105341e+00   
 74    9.19815850e+00    8.70254156e+00   -9.21213803e-01   |   9.19815850e+00    8.70254156e+00   -9.21213803e-01   
 75   -8.01803095e+00   -4.45817769e+00    5.57471884e+00   |  -8.01803095e+00   -4.45817769e+00    5.57471884e+00   
 76   -5.86253929e+00    5.83652577e+00   -6.34360165e+00   |  -5.86253929e+00    5.83652577e+00   -6.34360165e+00   
 77    6.06199260e+00   -2.48784919e+00   -5.08606488e+00   |   6.06199260e+00   -2.48784919e+00   -5.08606488e+00   
 78    1.18738835e+01   -3.73319855e+00   -4.38866196e-01   |   1.18738835e+01   -3.73319855e+00   -4.38866196e-01   
 79   -1.56385494e+01    5.79235960e+00   -1.99812910e+00   |  -1.56385494e+01    5.79235960e+00   -1.99812910e+00   
 80   -1.94391676e+01   -4.53538809e+00    4.36588740e+00   |  -1.94391676e+01   -4.53538809e+00    4.36588740e+00   
 81    9.31586770e+00    6.63326617e+00   -9.74173126e-01   |   9.31586770e+00    6.63326617e+00   -9.74173126e-01   
 82   -7.35390030e+00   -5.70406986e+00    2.20955436e+00   |  -7.35390030e+00   -5.70406986e+00    2.20955436e+00   
 83   -1.05651022e+01   -1.54295173e+00    7.24897928e+00   |  -1.05651022e+01   -1.54295173e+00    7.24897928e+00   
 84    1.36032888e+01    5.35391680e+00   -3.59291116e+00   |   1.36032888e+01    5.35391680e+00   -3.59291116e+00   
 85    4.54986724e+00   -7.37219893e+00    2.80877935e+00   |   4.54986724e+00   -7.37219893e+00    2.80877935e+00   
 86    9.49751983e+00   -1.31222356e+00   -8.09792389e+00   |   9.49751983e+00   -1.31222356e+00   -8.09792389e+00   
 87    8.80239867e+00    1.08579982e+01   -7.78201226e+00   |   8.80239867e+00    1.08579982e+01   -7.78201226e+00   
 88   -8.38964489e+00    8.26654738e+00    3.35799212e+00   |  -8.38964489e+00    8.26654738e+00    3.35799212e+00   
 89   -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   |  -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   
 90    3.92330889e+00    7.94576256e+00    1.64830722e+00   |   3.92330889e+00    7.94576256e+00    1.64830722e+00   
 91   -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   |  -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   
 92   -4.73119253e+00    2.74183833e+00    2.95416538e+00   |  -4.73119253e+00    2.74183833e+00    2.95416538e+00   
 93    4.58556057e+00   -8.92741912e-01    8.24098182e+00   |   4.58556057e+00   -8.92741912e-01    8.24098182e+00   
 94    2.46231815e+00    1.50440607e+00    7.82438921e+00   |   2.46231815e+00    1.50440607e+00    7.82438921e+00   
 95    3.70740224e+00   -1.01908010e+01    2.67681517e+00   |   3.70740224e+00   -1.01908010e+01    2.67681517e+00   
 96   -9.40050316e+00    5.19985655e+00   -3.58912196e+00   |  -9.40050316e+00    5.19985655e+00   -3.58912196e+00   
 97    5.74084207e+00    5.59845945e-01   -4.15851366e+00   |   5.74084207e+00    5.59845945e-01   -4.15851366e+00   
 98    9.45248391e+00   -2.88520175e+00   -1.04632055e+01   |   9.45248391e+00   -2.88520175e+00   -1.04632055e+01   
 99   -1.61041894e+01   -2.93900726e+00    1.98543964e+00   |  -1.61041894e+01   -2.93900726e+00    1.98543964e+00   
100   -6.33281408e+00   -1.35945667e+01    4.34669238e+00   |  -6.33281408e+00   -1.35945667e+01    4.34669238e+00   
101    1.71103505e+01    6.62305881e+00   -1.01409191e+00   |   1.71103505e+01    6.62305881e+00   -1.01409191e+00   
102    5.47027099e+00    6.90884501e+00   -9.51374318e-01   |   5.47027099e+00    6.90884501e+00   -9.51374318e-01   
103   -5.01432731e+00    2.72441699e-01    9.32289834e+00   |  -5.01432731e+00    2.72441699e-01    9.32289834e+00   
104   -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   |  -7.97115533e+00   -1.22486398e+00   -2.68210754e+00   
105    1.13507297e+01   -3.77203366e+00    2.22105341e+00   |   1.13507297e+01   -3.77203366e+00    2.22105341e+00   
106    9.19815850e+00    8.70254156e+00   -9.21213803e-01   |   9.19815850e+00    8.70254156e+00   -9.21213803e-01   
107   -8.01803095e+00   -4.45817769e+00    5.57471884e+00   |  -8.01803095e+00   -4.45817769e+00    5.57471884e+00   
108   -5.86253929e+00    5.83652577e+00   -6.34360165e+00   |  -5.86253929e+00    5.83652577e+00   -6.34360165e+00   
109    6.06199260e+00   -2.48784919e+00   -5.08606488e+00   |   6.06199260e+00   -2.48784919e+00   -5.08606488e+00   
110    1.18738835e+01   -3.73319855e+00   -4.38866196e-01   |   1.18738835e+01   -3.73319855e+00   -4.38866196e-01   
111   -1.56385494e+01    5.79235960e+00   -1.99812910e+00   |  -1.56385494e+01    5.79235960e+00   -1.99812910e+00   
112   -1.94391676e+01   -4.53538809e+00    4.36588740e+00   |  -1.94391676e+01   -4.53538809e+00    4.36588740e+00   
113    9.31586770e+00    6.63326617e+00   -9.74173126e-01   |   9.31586770e+00    6.63326617e+00   -9.74173126e-01   
114   -7.35390030e+00   -5.70406986e+00    2.20955436e+00   |  -7.35390030e+00   -5.70406986e+00    2.20955436e+00   
115   -1.05651022e+01   -1.54295173e+00    7.24897928e+00   |  -1.05651022e+01   -1.54295173e+00    7.24897928e+00   
116    1.36032888e+01    5.35391680e+00   -3.59291116e+00   |   1.36032888e+01    5.35391680e+00   -3.59291116e+00   
117    4.54986724e+00   -7.37219893e+00    2.80877935e+00   |   4.54986724e+00   -7.37219893e+00    2.80877935e+00   
118    9.49751983e+00   -1.31222356e+00   -8.09792389e+00   |   9.49751983e+00   -1.31222356e+00   -8.09792389e+00   
119    8.80239867e+00    1.08579982e+01   -7.78201226e+00   |   8.80239867e+00    1.08579982e+01   -7.78201226e+00   
120   -8.38964489e+00    8.26654738e+00    3.35799212e+00   |  -8.38964489e+00    8.26654738e+00    3.35799212e+00   
121   -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   |  -2.95146413e+00   -1.48605636e+01   -2.28836628e+00   
122    3.92330889e+00    7.94576256e+00    1.64830722e+00   |   3.92330889e+00    7.94576256e+00    1.64830722e+00   
123   -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   |  -8.93366338e+00   -1.69337297e+00   -6.40497666e+00   
124   -4.73119253e+00    2.74183833e+00    2.95416538e+00   |  -4.73119253e+00    2.74183833e+00    2.95416538e+00   
125    4.58556057e+00   -8.92741912e-01    8.24098182e+00   |   4.58556057e+00   -8.92741912e-01    8.24098182e+00   
126    2.46231815e+00    1.50440607e+00    7.82438921e+00   |   2.46231815e+00    1.50440607e+00    7.82438921e+00   
127    3.70740224e+00   -1.01908010e+01    2.67681517e+00   |   3.70740224e+00   -1.01908010e+01    2.67681517e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = FTF   (Configuration in file "config-CoCrCuFeNi-FTF.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 13.444812748852273
2^p V(r_1,...,r_N)    = 13.444812748852222

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -1.07817571e+01   -9.83801456e-01   -1.20711944e+01   |  -1.07817571e+01   -9.83801456e-01   -1.20711944e+01   
  1    6.56561621e+00    7.27413055e+00   -1.68428943e+01   |   6.56561621e+00    7.27413055e+00   -1.68428943e+01   
  2    6.51613401e+00   -5.89016497e+00    1.16887057e+01   |   6.51613401e+00   -5.89016497e+00    1.16887057e+01   
  3   -1.21626870e+01    9.10503673e+00    5.89555972e+00   |  -1.21626870e+01    9.10503673e+00    5.89555972e+00   
  4   -1.76282912e+00   -4.97980006e+00   -7.24405263e+00   |  -1.76282912e+00   -4.97980006e+00   -7.24405263e+00   
  5    8.58465999e+00    4.24367256e+00   -4.85385122e+00   |   8.58465999e+00    4.24367256e+00   -4.85385122e+00   
  6    9.56717233e+00    7.11842062e+00   -1.07095149e+01   |   9.56717233e+00    7.11842062e+00   -1.07095149e+01   
  7    2.63476014e+00   -1.22532569e+00    8.70034171e+00   |   2.63476014e+00   -1.22532569e+00    8.70034171e+00   
  8   -7.80184991e+00   -2.53976215e+00   -7.46332304e+00   |  -7.80184991e+00   -2.53976215e+00   -7.46332304e+00   
  9    6.63981474e+00    2.12265538e+00   -1.18249824e+01   |   6.63981474e+00    2.12265538e+00   -1.18249824e+01   
 10   -1.03305300e+01    1.45086424e+00    2.11556884e+01   |  -1.03305300e+01    1.45086424e+00    2.11556884e+01   
 11   -1.12816091e+01   -3.97180913e+00    8.68750653e+00   |  -1.12816091e+01   -3.97180913e+00    8.68750653e+00   
 12    1.12867622e+01   -2.90782747e+00   -2.24669837e+01   |   1.12867622e+01   -2.90782747e+00   -2.24669837e+01   
 13    4.96920014e+00    8.50398118e+00   -1.24744495e+01   |   4.96920014e+00    8.50398118e+00   -1.24744495e+01   
 14    3.86185485e+00   -1.22463835e+01    1.45662617e+01   |   3.86185485e+00   -1.22463835e+01    1.45662617e+01   
 15   -5.85519968e+00   -4.92666846e+00    3.98618170e+00   |  -5.85519968e+00   -4.92666846e+00    3.98618170e+00   
 16   -6.52099787e+00   -4.74293696e+00    4.83074292e+00   |  -6.52099787e+00   -4.74293696e+00    4.83074292e+00   
 17    8.27355155e+00   -1.70480481e+00   -4.31558484e+00   |   8.27355155e+00   -1.70480481e+00   -4.31558484e+00   
 18    7.36946354e-01    4.04056353e+00    5.73710262e+00   |   7.36946354e-01    4.04056353e+00    5.73710262e+00   
 19   -8.03215230e+00   -3.69090207e+00    7.60772789e+00   |  -8.03215230e+00   -3.69090207e+00    7.60772789e+00   
 20   -1.52414105e+01    2.25892319e+00   -3.11654370e-01   |  -1.52414105e+01    2.25892319e+00   -3.11654370e-01   
 21    8.56432926e+00    5.12328147e+00   -3.95607675e+00   |   8.56432926e+00    5.12328147e+00   -3.95607675e+00   
 22    7.75730017e+00    3.51067508e+00    1.09918456e+01   |   7.75730017e+00    3.51067508e+00    1.09918456e+01   
 23   -1.14063072e+00    2.05683845e+00    9.32726710e+00   |  -1.14063072e+00    2.05683845e+00    9.32726710e+00   
 24   -9.54951752e+00   -2.30309718e+00   -1.36741524e+01   |  -9.54951752e+00   -2.30309718e+00   -1.36741524e+01   
 25    1.30972589e+01    1.45677928e+00   -1.30341583e+01   |   1.30972589e+01    1.45677928e+00   -1.30341583e+01   
 26    1.71931451e+01   -1.35638422e+01    1.34859565e+01   |   1.71931451e+01   -1.35638422e+01    1.34859565e+01   
 27   -2.37273012e+01    1.44237628e+01    1.11175218e+01   |  -2.37273012e+01    1.44237628e+01    1.11175218e+01   
 28   -5.10542031e+00    7.17115206e+00   -5.97415901e+00   |  -5.10542031e+00    7.17115206e+00   -5.97415901e+00   
 29    1.17204836e+01   -9.75106103e+00   -2.01835514e+00   |   1.17204836e+01   -9.75106103e+00   -2.01835514e+00   
 30    1.07037537e+01   -6.01095123e+00    4.38390519e+00   |   1.07037537e+01   -6.01095123e+00    4.38390519e+00   
 31   -9.37885114e+00    1.57840123e+00    7.07307190e+00   |  -9.37885114e+00    1.57840123e+00    7.07307190e+00   
 32   -1.07817571e+01   -9.83801456e-01   -1.20711944e+01   |  -1.07817571e+01   -9.83801456e-01   -1.20711944e+01   
 33    6.56561621e+00    7.27413055e+00   -1.68428943e+01   |   6.56561621e+00    7.27413055e+00   -1.68428943e+01   
 34    6.51613401e+00   -5.89016497e+00    1.16887057e+01   |   6.51613401e+00   -5.89016497e+00    1.16887057e+01   
 35   -1.21626870e+01    9.10503673e+00    5.89555972e+00   |  -1.21626870e+01    9.10503673e+00    5.89555972e+00   
 36   -1.76282912e+00   -4.97980006e+00   -7.24405263e+00   |  -1.76282912e+00   -4.97980006e+00   -7.24405263e+00   
 37    8.58465999e+00    4.24367256e+00   -4.85385122e+00   |   8.58465999e+00    4.24367256e+00   -4.85385122e+00   
 38    9.56717233e+00    7.11842062e+00   -1.07095149e+01   |   9.56717233e+00    7.11842062e+00   -1.07095149e+01   
 39    2.63476014e+00   -1.22532569e+00    8.70034171e+00   |   2.63476014e+00   -1.22532569e+00    8.70034171e+00   
 40   -7.80184991e+00   -2.53976215e+00   -7.46332304e+00   |  -7.80184991e+00   -2.53976215e+00   -7.46332304e+00   
 41    6.63981474e+00    2.12265538e+00   -1.18249824e+01   |   6.63981474e+00    2.12265538e+00   -1.18249824e+01   
 42   -1.03305300e+01    1.45086424e+00    2.11556884e+01   |  -1.03305300e+01    1.45086424e+00    2.11556884e+01   
 43   -1.12816091e+01   -3.97180913e+00    8.68750653e+00   |  -1.12816091e+01   -3.97180913e+00    8.68750653e+00   
 44    1.12867622e+01   -2.90782747e+00   -2.24669837e+01   |   1.12867622e+01   -2.90782747e+00   -2.24669837e+01   
 45    4.96920014e+00    8.50398118e+00   -1.24744495e+01   |   4.96920014e+00    8.50398118e+00   -1.24744495e+01   
 46    3.86185485e+00   -1.22463835e+01    1.45662617e+01   |   3.86185485e+00   -1.22463835e+01    1.45662617e+01   
 47   -5.85519968e+00   -4.92666846e+00    3.98618170e+00   |  -5.85519968e+00   -4.92666846e+00    3.98618170e+00   
 48   -6.52099787e+00   -4.74293696e+00    4.83074292e+00   |  -6.52099787e+00   -4.74293696e+00    4.83074292e+00   
 49    8.27355155e+00   -1.70480481e+00   -4.31558484e+00   |   8.27355155e+00   -1.70480481e+00   -4.31558484e+00   
 50    7.36946354e-01    4.04056353e+00    5.73710262e+00   |   7.36946354e-01    4.04056353e+00    5.73710262e+00   
 51   -8.03215230e+00   -3.69090207e+00    7.60772789e+00   |  -8.03215230e+00   -3.69090207e+00    7.60772789e+00   
 52   -1.52414105e+01    2.25892319e+00   -3.11654370e-01   |  -1.52414105e+01    2.25892319e+00   -3.11654370e-01   
 53    8.56432926e+00    5.12328147e+00   -3.95607675e+00   |   8.56432926e+00    5.12328147e+00   -3.95607675e+00   
 54    7.75730017e+00    3.51067508e+00    1.09918456e+01   |   7.75730017e+00    3.51067508e+00    1.09918456e+01   
 55   -1.14063072e+00    2.05683845e+00    9.32726710e+00   |  -1.14063072e+00    2.05683845e+00    9.32726710e+00   
 56   -9.54951752e+00   -2.30309718e+00   -1.36741524e+01   |  -9.54951752e+00   -2.30309718e+00   -1.36741524e+01   
 57    1.30972589e+01    1.45677928e+00   -1.30341583e+01   |   1.30972589e+01    1.45677928e+00   -1.30341583e+01   
 58    1.71931451e+01   -1.35638422e+01    1.34859565e+01   |   1.71931451e+01   -1.35638422e+01    1.34859565e+01   
 59   -2.37273012e+01    1.44237628e+01    1.11175218e+01   |  -2.37273012e+01    1.44237628e+01    1.11175218e+01   
 60   -5.10542031e+00    7.17115206e+00   -5.97415901e+00   |  -5.10542031e+00    7.17115206e+00   -5.97415901e+00   
 61    1.17204836e+01   -9.75106103e+00   -2.01835514e+00   |   1.17204836e+01   -9.75106103e+00   -2.01835514e+00   
 62    1.07037537e+01   -6.01095123e+00    4.38390519e+00   |   1.07037537e+01   -6.01095123e+00    4.38390519e+00   
 63   -9.37885114e+00    1.57840123e+00    7.07307190e+00   |  -9.37885114e+00    1.57840123e+00    7.07307190e+00   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------

MIXED STRUCTURE -- Species = Co Cr Cu Fe Ni, PBC = FFT   (Configuration in file "config-CoCrCuFeNi-FFT.xyz")
------------------------------------------------------------------------------------------------------------------------

The system is doubled in p=1 periodic directions, which means an increase by a factor n=2^1=2
in the number of atoms and in the energy.

Energy requirement:

V(DBL_p(r_1,...,r_N)) = (2^p) V(r_1,...,r_N), where r_i is the position of atom i, V is the potential energy, 
and DBL_p is an operator that doubles the configuration in p periodic directions.

V(DBL_p(r_1,...,r_N)) = 8.939688972059047
2^p V(r_1,...,r_N)    = 8.939688972059514

Forces requirement:

f_k(DBL_p(r_1,...,r_N)) = f_(k % N)(r_1,...,r_N), where r_i is the position of atom i, f_k is the force on atom k 
(where k runs from 1 to the number of atoms in the doubled configuration), DBL_p doubles the configuration 
in p periodic directions, N is the number of atoms in the original configuration, and % is the modulo operator.

  k                 f_k(DBL_p(r_1,...,r_N))                                  f_(k % N)(r_1,...,r_N)
------------------------------------------------------------------------------------------------------------------------
  0   -6.98260267e+00   -1.50619798e+01    6.32827732e+00   |  -6.98260267e+00   -1.50619798e+01    6.32827732e+00   
  1    1.38605808e+00    4.62272085e+00   -1.80639470e+00   |   1.38605808e+00    4.62272085e+00   -1.80639470e+00   
  2   -1.33126673e+01   -1.44025459e+01   -1.43936858e+01   |  -1.33126673e+01   -1.44025459e+01   -1.43936858e+01   
  3   -1.02400236e+01    5.42742721e+00    2.55003569e+00   |  -1.02400236e+01    5.42742721e+00    2.55003569e+00   
  4   -6.46620195e-01   -9.78152691e+00   -6.40989145e+00   |  -6.46620195e-01   -9.78152691e+00   -6.40989145e+00   
  5    9.64195718e+00    6.40977862e+00   -1.08952354e+00   |   9.64195718e+00    6.40977862e+00   -1.08952354e+00   
  6    1.01059944e+01   -6.59514455e+00    3.49821066e+00   |   1.01059944e+01   -6.59514455e+00    3.49821066e+00   
  7    7.98887651e+00   -2.56508260e+00   -2.94752821e+00   |   7.98887651e+00   -2.56508260e+00   -2.94752821e+00   
  8   -6.56380427e+00    2.24205039e+00   -3.78432990e+00   |  -6.56380427e+00    2.24205039e+00   -3.78432990e+00   
  9   -3.25685913e+01    8.93884878e+00    3.23190637e+01   |  -3.25685913e+01    8.93884878e+00    3.23190637e+01   
 10   -1.18927833e+01    8.59812732e+00    1.54305819e+00   |  -1.18927833e+01    8.59812732e+00    1.54305819e+00   
 11   -1.59234699e+01    1.15603856e+01   -1.25058317e+01   |  -1.59234699e+01    1.15603856e+01   -1.25058317e+01   
 12    1.67475026e+00   -4.95062148e+00   -5.04035622e+00   |   1.67475026e+00   -4.95062148e+00   -5.04035622e+00   
 13    1.01366440e+01    6.54738578e+00    5.09629836e-01   |   1.01366440e+01    6.54738578e+00    5.09629836e-01   
 14    8.90612115e+00   -1.74528722e+00   -4.70219218e-01   |   8.90612115e+00   -1.74528722e+00   -4.70219218e-01   
 15   -7.98545043e-01    1.06505455e+01    4.46393026e+00   |  -7.98545043e-01    1.06505455e+01    4.46393026e+00   
 16   -5.42809060e+00   -6.32714450e+00    6.59761222e+00   |  -5.42809060e+00   -6.32714450e+00    6.59761222e+00   
 17   -1.14236452e+01    1.28748856e+01    1.11272621e+01   |  -1.14236452e+01    1.28748856e+01    1.11272621e+01   
 18   -1.68695112e+00   -1.47631035e+01   -3.92117178e+00   |  -1.68695112e+00   -1.47631035e+01   -3.92117178e+00   
 19   -8.38401498e+00    9.15014536e+00   -1.27875536e+01   |  -8.38401498e+00    9.15014536e+00   -1.27875536e+01   
 20    1.88399312e+01   -1.50219410e+01    1.64130570e+01   |   1.88399312e+01   -1.50219410e+01    1.64130570e+01   
 21    7.42647640e+00   -8.58963406e-01    3.48562374e+00   |   7.42647640e+00   -8.58963406e-01    3.48562374e+00   
 22    5.27248048e+00   -4.53962433e+00   -2.11370556e+00   |   5.27248048e+00   -4.53962433e+00   -2.11370556e+00   
 23    4.50296000e+00    9.16563098e+00   -4.89412412e+00   |   4.50296000e+00    9.16563098e+00   -4.89412412e+00   
 24   -9.42968808e+00   -1.28160864e+01   -1.57843634e+00   |  -9.42968808e+00   -1.28160864e+01   -1.57843634e+00   
 25    1.90418989e+01    6.17412793e+00    7.14072299e+00   |   1.90418989e+01    6.17412793e+00    7.14072299e+00   
 26    3.44774410e+00   -8.65433522e+00    3.89095973e+00   |   3.44774410e+00   -8.65433522e+00    3.89095973e+00   
 27   -6.77153144e+00    8.17161469e+00    4.59240218e+00   |  -6.77153144e+00    8.17161469e+00    4.59240218e+00   
 28   -2.15636208e-01    2.81566286e+00    5.84767034e+00   |  -2.15636208e-01    2.81566286e+00    5.84767034e+00   
 29    9.86409152e-01    6.09076073e+00   -7.91831313e-01   |   9.86409152e-01    6.09076073e+00   -7.91831313e-01   
 30    6.12059364e+00   -9.66625020e+00   -5.82568996e-01   |   6.12059364e+00   -9.66625020e+00   -5.82568996e-01   
 31    2.67897695e+01    8.30953882e+00   -3.51903636e+01   |   2.67897695e+01    8.30953882e+00   -3.51903636e+01   
 32   -6.98260267e+00   -1.50619798e+01    6.32827732e+00   |  -6.98260267e+00   -1.50619798e+01    6.32827732e+00   
 33    1.38605808e+00    4.62272085e+00   -1.80639470e+00   |   1.38605808e+00    4.62272085e+00   -1.80639470e+00   
 34   -1.33126673e+01   -1.44025459e+01   -1.43936858e+01   |  -1.33126673e+01   -1.44025459e+01   -1.43936858e+01   
 35   -1.02400236e+01    5.42742721e+00    2.55003569e+00   |  -1.02400236e+01    5.42742721e+00    2.55003569e+00   
 36   -6.46620195e-01   -9.78152691e+00   -6.40989145e+00   |  -6.46620195e-01   -9.78152691e+00   -6.40989145e+00   
 37    9.64195718e+00    6.40977862e+00   -1.08952354e+00   |   9.64195718e+00    6.40977862e+00   -1.08952354e+00   
 38    1.01059944e+01   -6.59514455e+00    3.49821066e+00   |   1.01059944e+01   -6.59514455e+00    3.49821066e+00   
 39    7.98887651e+00   -2.56508260e+00   -2.94752821e+00   |   7.98887651e+00   -2.56508260e+00   -2.94752821e+00   
 40   -6.56380427e+00    2.24205039e+00   -3.78432990e+00   |  -6.56380427e+00    2.24205039e+00   -3.78432990e+00   
 41   -3.25685913e+01    8.93884878e+00    3.23190637e+01   |  -3.25685913e+01    8.93884878e+00    3.23190637e+01   
 42   -1.18927833e+01    8.59812732e+00    1.54305819e+00   |  -1.18927833e+01    8.59812732e+00    1.54305819e+00   
 43   -1.59234699e+01    1.15603856e+01   -1.25058317e+01   |  -1.59234699e+01    1.15603856e+01   -1.25058317e+01   
 44    1.67475026e+00   -4.95062148e+00   -5.04035622e+00   |   1.67475026e+00   -4.95062148e+00   -5.04035622e+00   
 45    1.01366440e+01    6.54738578e+00    5.09629836e-01   |   1.01366440e+01    6.54738578e+00    5.09629836e-01   
 46    8.90612115e+00   -1.74528722e+00   -4.70219218e-01   |   8.90612115e+00   -1.74528722e+00   -4.70219218e-01   
 47   -7.98545043e-01    1.06505455e+01    4.46393026e+00   |  -7.98545043e-01    1.06505455e+01    4.46393026e+00   
 48   -5.42809060e+00   -6.32714450e+00    6.59761222e+00   |  -5.42809060e+00   -6.32714450e+00    6.59761222e+00   
 49   -1.14236452e+01    1.28748856e+01    1.11272621e+01   |  -1.14236452e+01    1.28748856e+01    1.11272621e+01   
 50   -1.68695112e+00   -1.47631035e+01   -3.92117178e+00   |  -1.68695112e+00   -1.47631035e+01   -3.92117178e+00   
 51   -8.38401498e+00    9.15014536e+00   -1.27875536e+01   |  -8.38401498e+00    9.15014536e+00   -1.27875536e+01   
 52    1.88399312e+01   -1.50219410e+01    1.64130570e+01   |   1.88399312e+01   -1.50219410e+01    1.64130570e+01   
 53    7.42647640e+00   -8.58963406e-01    3.48562374e+00   |   7.42647640e+00   -8.58963406e-01    3.48562374e+00   
 54    5.27248048e+00   -4.53962433e+00   -2.11370556e+00   |   5.27248048e+00   -4.53962433e+00   -2.11370556e+00   
 55    4.50296000e+00    9.16563098e+00   -4.89412412e+00   |   4.50296000e+00    9.16563098e+00   -4.89412412e+00   
 56   -9.42968808e+00   -1.28160864e+01   -1.57843634e+00   |  -9.42968808e+00   -1.28160864e+01   -1.57843634e+00   
 57    1.90418989e+01    6.17412793e+00    7.14072299e+00   |   1.90418989e+01    6.17412793e+00    7.14072299e+00   
 58    3.44774410e+00   -8.65433522e+00    3.89095973e+00   |   3.44774410e+00   -8.65433522e+00    3.89095973e+00   
 59   -6.77153144e+00    8.17161469e+00    4.59240218e+00   |  -6.77153144e+00    8.17161469e+00    4.59240218e+00   
 60   -2.15636208e-01    2.81566286e+00    5.84767034e+00   |  -2.15636208e-01    2.81566286e+00    5.84767034e+00   
 61    9.86409152e-01    6.09076073e+00   -7.91831313e-01   |   9.86409152e-01    6.09076073e+00   -7.91831313e-01   
 62    6.12059364e+00   -9.66625020e+00   -5.82568996e-01   |   6.12059364e+00   -9.66625020e+00   -5.82568996e-01   
 63    2.67897695e+01    8.30953882e+00   -3.51903636e+01   |   2.67897695e+01    8.30953882e+00   -3.51903636e+01   
------------------------------------------------------------------------------------------------------------------------
PASS: Energies and forces are the same to within a relative error of 1e-08
------------------------------------------------------------------------------------------------------------------------
========================================================================================================================

========================================================================================================================
To pass this verification check the model must correctly support periodic boundary conditions for all configurations it was able to compute.

Grade: P

Comment: Periodic boundary conditions were correctly supported for all configurations that the model was able to compute.


=== Verification check vc-periodicity-support end (2022-11-29 18:16:32) ===