Element = Lattice = Model = Element: Pb
Lattice: hcp
Model: MEAM_LAMMPS_EtesamiBaskesLaradji_2018_PbSn__MO_162736908871_002
Computed model cutoff of 5.500000007003557 Angstroms
Computed isolated atomic energy of 0.0 eV for species Pb

==============================================================================
==============================================================================
 Starting optimization to find optimum lattice constant 'a' with c/a fixed to
 sqrt(8/3)
==============================================================================
==============================================================================


Attempting to perform relaxation using initial lattice constant guess of a = 1.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 41
         Function evaluations: 86
Results for this minimization:
  a = 3.500486122258012, total energy = -8.149513991074487

Attempting to perform relaxation using initial lattice constant guess of a = 1.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 41
         Function evaluations: 86
Results for this minimization:
  a = 3.5004861027002327, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 1.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 3.500486083328724, total energy = -8.149513991074487

Attempting to perform relaxation using initial lattice constant guess of a = 1.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 40
         Function evaluations: 86
Results for this minimization:
  a = 3.5004861138761134, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 1.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 39
         Function evaluations: 84
Results for this minimization:
  a = 3.5004861027002385, total energy = -8.149513991074492

Attempting to perform relaxation using initial lattice constant guess of a = 1.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 83
Results for this minimization:
  a = 3.50048611313105, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 1.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 3.5004860941320652, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 1.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 79
Results for this minimization:
  a = 3.5004861038178205, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 2.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 76
Results for this minimization:
  a = 3.5004861027002363, total energy = -8.149513991074492

Attempting to perform relaxation using initial lattice constant guess of a = 2.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 77
Results for this minimization:
  a = 3.5004861051216736, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 2.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 78
Results for this minimization:
  a = 3.5004861027002345, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 2.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 78
Results for this minimization:
  a = 3.500486104190346, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 2.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 36
         Function evaluations: 77
Results for this minimization:
  a = 3.5004861131310463, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 2.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 81
Results for this minimization:
  a = 3.500486103259029, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 2.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 35
         Function evaluations: 75
Results for this minimization:
  a = 3.500486113876107, total energy = -8.149513991074485

Attempting to perform relaxation using initial lattice constant guess of a = 2.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 35
         Function evaluations: 75
Results for this minimization:
  a = 3.5004860945045952, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 3.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 34
         Function evaluations: 73
Results for this minimization:
  a = 3.5004860937595383, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 3.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 33
         Function evaluations: 71
Results for this minimization:
  a = 3.5004860907793045, total energy = -8.149513991074485

Attempting to perform relaxation using initial lattice constant guess of a = 3.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 33
         Function evaluations: 72
Results for this minimization:
  a = 3.500486113131047, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 3.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 32
         Function evaluations: 68
Results for this minimization:
  a = 3.500486102700234, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 3.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 33
         Function evaluations: 71
Results for this minimization:
  a = 3.5004860941320652, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 3.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 33
         Function evaluations: 73
Results for this minimization:
  a = 3.5004860941320652, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 3.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 34
         Function evaluations: 71
Results for this minimization:
  a = 3.5004861060879193, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 3.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 34
         Function evaluations: 73
Results for this minimization:
  a = 3.500486094877123, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 4.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 34
         Function evaluations: 72
Results for this minimization:
  a = 3.500486093387007, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 4.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 34
         Function evaluations: 73
Results for this minimization:
  a = 3.500486113876104, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 4.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 36
         Function evaluations: 76
Results for this minimization:
  a = 3.5004861051216714, total energy = -8.149513991074487

Attempting to perform relaxation using initial lattice constant guess of a = 4.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 78
Results for this minimization:
  a = 3.5004861182533205, total energy = -8.149513991074485

Attempting to perform relaxation using initial lattice constant guess of a = 4.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 36
         Function evaluations: 77
Results for this minimization:
  a = 3.5004861024906835, total energy = -8.149513991074492

Attempting to perform relaxation using initial lattice constant guess of a = 4.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 81
Results for this minimization:
  a = 3.5004861176945257, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 4.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 80
Results for this minimization:
  a = 3.500486096227542, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 4.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 81
Results for this minimization:
  a = 3.5004860946675747, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 5.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 83
Results for this minimization:
  a = 3.5004861131310463, total energy = -8.149513991074489

Attempting to perform relaxation using initial lattice constant guess of a = 5.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 83
Results for this minimization:
  a = 3.5004861070658047, total energy = -8.14951399107449

Attempting to perform relaxation using initial lattice constant guess of a = 5.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 38
         Function evaluations: 81
Results for this minimization:
  a = 3.5004861159715794, total energy = -8.149513991074487

Attempting to perform relaxation using initial lattice constant guess of a = 5.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 37
         Function evaluations: 80
Results for this minimization:
  a = 3.5004861059132972, total energy = -8.149513991074487

Attempting to perform relaxation using initial lattice constant guess of a = 5.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 39
         Function evaluations: 82
Results for this minimization:
  a = 3.500486113876102, total energy = -8.149513991074492

Attempting to perform relaxation using initial lattice constant guess of a = 5.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -8.149514
         Iterations: 39
         Function evaluations: 85
Results for this minimization:
  a = 3.500486110977363, total energy = -8.149513991074487

==============================================================================
==============================================================================
 Starting optimization with both a and c/a relaxed
==============================================================================
==============================================================================


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 4.573015895103626 = ([1.30639453] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 4.858829388547602 = ([1.38804419] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 5.144642881991579 = ([1.46969385] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 5.430456375435555 = ([1.5513435] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 5.7162698688795315 = ([1.63299316] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 6.002083362323508 = ([1.71464282] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 6.287896855767484 = ([1.79629248] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 6.573710349211461 = ([1.87794214] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = [3.5004861] Angstroms and c = 6.859523842655437 = ([1.95959179] * a) Angstroms

     Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 5.625 Angstroms
     Exception message:
setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
     Continuing...


==============================================================================
==============================================================================
 Finished with optimization
==============================================================================
==============================================================================

 Final lattice Constants:
   a = [3.5004861] Angstroms, c = [5.71626987] Angstroms, c/a = 1.632993

 Total energy: -8.149513991074492 eV

 Cohesive energy: -2.037378497768623 eV/atom

==============================================================================
==============================================================================