Element = Lattice = Model = Element: Sn
Lattice: hcp
Model: LJ_ElliottAkerson_2015_Universal__MO_959249795837_003
Computed model cutoff of 9.906790000200273 Angstroms
Computed isolated atomic energy of 0.0 eV for species Sn

==============================================================================
==============================================================================
 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: -63.304757
         Iterations: 38
         Function evaluations: 79
Results for this minimization:
  a = 2.7037452962249553, total energy = -63.3047573888728

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: -63.304757
         Iterations: 40
         Function evaluations: 85
Results for this minimization:
  a = 2.7037452757358538, total energy = -63.304757388872765

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: -63.304757
         Iterations: 38
         Function evaluations: 81
Results for this minimization:
  a = 2.703745275735855, total energy = -63.30475738887273

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: -63.304757
         Iterations: 39
         Function evaluations: 82
Results for this minimization:
  a = 2.7037453010096275, total energy = -63.30475738887272

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: -63.304757
         Iterations: 39
         Function evaluations: 83
Results for this minimization:
  a = 2.703745320439342, total energy = -63.30475738887265

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: -63.304757
         Iterations: 37
         Function evaluations: 80
Results for this minimization:
  a = 2.7037453204393396, total energy = -63.304757388872595

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: -63.304757
         Iterations: 37
         Function evaluations: 79
Results for this minimization:
  a = 2.7037452975288048, total energy = -63.304757388873014

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: -63.304757
         Iterations: 36
         Function evaluations: 79
Results for this minimization:
  a = 2.703745277132839, total energy = -63.30475738887291

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: -63.304757
         Iterations: 36
         Function evaluations: 76
Results for this minimization:
  a = 2.7037452951073666, total energy = -63.30475738887274

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: -63.304757
         Iterations: 34
         Function evaluations: 73
Results for this minimization:
  a = 2.7037453044205915, total energy = -63.304757388872616

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: -63.304757
         Iterations: 37
         Function evaluations: 80
Results for this minimization:
  a = 2.7037452825461514, total energy = -63.304757388873

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: -63.304757
         Iterations: 37
         Function evaluations: 80
Results for this minimization:
  a = 2.703745313151739, total energy = -63.30475738887267

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: -63.304757
         Iterations: 33
         Function evaluations: 71
Results for this minimization:
  a = 2.703745275735855, total energy = -63.304757388872744

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: -63.304757
         Iterations: 33
         Function evaluations: 72
Results for this minimization:
  a = 2.7037452662363655, total energy = -63.30475738887292

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: -63.304757
         Iterations: 33
         Function evaluations: 71
Results for this minimization:
  a = 2.703745298832655, total energy = -63.30475738887281

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: -63.304757
         Iterations: 34
         Function evaluations: 75
Results for this minimization:
  a = 2.703745290369261, total energy = -63.304757388872794

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: -63.304757
         Iterations: 34
         Function evaluations: 73
Results for this minimization:
  a = 2.7037452804856006, total energy = -63.30475738887287

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: -63.304757
         Iterations: 36
         Function evaluations: 77
Results for this minimization:
  a = 2.703745288599748, total energy = -63.30475738887286

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: -63.304757
         Iterations: 35
         Function evaluations: 76
Results for this minimization:
  a = 2.703745320439338, total energy = -63.304757388872595

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: -63.304757
         Iterations: 35
         Function evaluations: 76
Results for this minimization:
  a = 2.703745262167649, total energy = -63.30475738887282

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: -63.304757
         Iterations: 36
         Function evaluations: 77
Results for this minimization:
  a = 2.703745297528803, total energy = -63.30475738887296

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: -63.304757
         Iterations: 36
         Function evaluations: 75
Results for this minimization:
  a = 2.703745289123615, total energy = -63.30475738887306

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: -63.304757
         Iterations: 37
         Function evaluations: 80
Results for this minimization:
  a = 2.703745277132839, total energy = -63.30475738887296

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: -63.304757
         Iterations: 36
         Function evaluations: 76
Results for this minimization:
  a = 2.703745297950805, total energy = -63.30475738887272

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: -63.304757
         Iterations: 37
         Function evaluations: 78
Results for this minimization:
  a = 2.7037452949210996, total energy = -63.30475738887269

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: -63.304757
         Iterations: 37
         Function evaluations: 79
Results for this minimization:
  a = 2.70374528100074, total energy = -63.30475738887296

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: -63.304757
         Iterations: 39
         Function evaluations: 83
Results for this minimization:
  a = 2.703745258506385, total energy = -63.30475738887271

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: -63.304757
         Iterations: 38
         Function evaluations: 82
Results for this minimization:
  a = 2.7037452571094036, total energy = -63.30475738887257

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: -63.304757
         Iterations: 40
         Function evaluations: 86
Results for this minimization:
  a = 2.703745282546146, total energy = -63.30475738887308

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: -63.304757
         Iterations: 39
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452692165957, total energy = -63.30475738887302

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: -63.304757
         Iterations: 40
         Function evaluations: 86
Results for this minimization:
  a = 2.703745305631311, total energy = -63.30475738887271

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: -63.304757
         Iterations: 38
         Function evaluations: 83
Results for this minimization:
  a = 2.7037452623248064, total energy = -63.30475738887265

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: -63.304757
         Iterations: 39
         Function evaluations: 86
Results for this minimization:
  a = 2.703745290171355, total energy = -63.30475738887277

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: -63.304757
         Iterations: 41
         Function evaluations: 87
Results for this minimization:
  a = 2.703745298818098, total energy = -63.304757388872765

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: -63.304757
         Iterations: 39
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452662363637, total energy = -63.30475738887284

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: -63.304757
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452958087687, total energy = -63.30475738887271

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: -63.304757
         Iterations: 40
         Function evaluations: 86
Results for this minimization:
  a = 2.703745280904692, total energy = -63.304757388873

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: -63.304757
         Iterations: 38
         Function evaluations: 80
Results for this minimization:
  a = 2.703745274688117, total energy = -63.30475738887278

Attempting to perform relaxation using initial lattice constant guess of a = 5.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 41
         Function evaluations: 88
Results for this minimization:
  a = 2.7037452970631364, total energy = -63.304757388872936

Attempting to perform relaxation using initial lattice constant guess of a = 5.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 41
         Function evaluations: 87
Results for this minimization:
  a = 2.7037453068187425, total energy = -63.304757388872645

Attempting to perform relaxation using initial lattice constant guess of a = 6.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 87
Results for this minimization:
  a = 2.7037452804855935, total energy = -63.304757388872865

Attempting to perform relaxation using initial lattice constant guess of a = 6.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 38
         Function evaluations: 80
Results for this minimization:
  a = 2.7037452662363615, total energy = -63.304757388872794

Attempting to perform relaxation using initial lattice constant guess of a = 6.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 39
         Function evaluations: 83
Results for this minimization:
  a = 2.70374528830871, total energy = -63.304757388872865

Attempting to perform relaxation using initial lattice constant guess of a = 6.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 2.7037453064738637, total energy = -63.30475738887273

Attempting to perform relaxation using initial lattice constant guess of a = 6.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 39
         Function evaluations: 83
Results for this minimization:
  a = 2.7037453204393316, total energy = -63.304757388872574

Attempting to perform relaxation using initial lattice constant guess of a = 6.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 39
         Function evaluations: 84
Results for this minimization:
  a = 2.7037453066557564, total energy = -63.30475738887272

Attempting to perform relaxation using initial lattice constant guess of a = 6.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452868418725, total energy = -63.30475738887282

Attempting to perform relaxation using initial lattice constant guess of a = 6.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 39
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452957592905, total energy = -63.30475738887269

Attempting to perform relaxation using initial lattice constant guess of a = 7.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 85
Results for this minimization:
  a = 2.703745297528803, total energy = -63.30475738887296

Attempting to perform relaxation using initial lattice constant guess of a = 7.125 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 39
         Function evaluations: 81
Results for this minimization:
  a = 2.703745262997103, total energy = -63.304757388872645

Attempting to perform relaxation using initial lattice constant guess of a = 7.25 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 86
Results for this minimization:
  a = 2.7037452708929686, total energy = -63.304757388872794

Attempting to perform relaxation using initial lattice constant guess of a = 7.375 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 41
         Function evaluations: 89
Results for this minimization:
  a = 2.703745301347222, total energy = -63.30475738887306

Attempting to perform relaxation using initial lattice constant guess of a = 7.5 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 41
         Function evaluations: 89
Results for this minimization:
  a = 2.70374528830871, total energy = -63.30475738887287

Attempting to perform relaxation using initial lattice constant guess of a = 7.625 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 87
Results for this minimization:
  a = 2.703745240718132, total energy = -63.30475738887233

Attempting to perform relaxation using initial lattice constant guess of a = 7.75 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 84
Results for this minimization:
  a = 2.7037452979507943, total energy = -63.304757388872716

Attempting to perform relaxation using initial lattice constant guess of a = 7.875 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 85
Results for this minimization:
  a = 2.7037452626915086, total energy = -63.30475738887261

Attempting to perform relaxation using initial lattice constant guess of a = 8.0 Angstroms (c/a fixed at sqrt(8/3))

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 40
         Function evaluations: 85
Results for this minimization:
  a = 2.7037452988326507, total energy = -63.304757388872694

Attempting to perform relaxation using initial lattice constant guess of a = 8.125 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.125 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8125 Angstroms and c = -1.3268069440075547 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.25 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.25 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8249999999999922 Angstroms and c = -1.3472193585307353 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.375 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.375 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8375000000000234 Angstroms and c = -1.3676317730539793 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.5 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.5 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8500000000000156 Angstroms and c = -1.3880441875771599 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.625 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.625 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8625000000000078 Angstroms and c = -1.4084566021003402 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.75 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.75 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.875 Angstroms and c = -1.4288690166235205 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 8.875 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 8.875 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.8874999999999922 Angstroms and c = -1.449281431146701 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.0 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.0 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9000000000000234 Angstroms and c = -1.469693845669945 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.125 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.125 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9125000000000156 Angstroms and c = -1.4901062601931256 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.25 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.25 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9250000000000078 Angstroms and c = -1.510518674716306 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.375 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.375 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9375 Angstroms and c = -1.5309310892394863 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.5 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.5 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9499999999999922 Angstroms and c = -1.5513435037626666 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.625 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.625 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9625000000000234 Angstroms and c = -1.5717559182859109 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.75 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.75 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9750000000000156 Angstroms and c = -1.5921683328090912 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 9.875 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 9.875 Angstroms
Exception message:
Attempted to evaluate energy at a = -0.9875000000000078 Angstroms and c = -1.6125807473322717 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


Attempting to perform relaxation using initial lattice constant guess of a = 10.0 Angstroms (c/a fixed at sqrt(8/3))

Failed to perform relaxation w.r.t. 'a' with c/a fixed at sqrt(8/3) and an initial guess of a = 10.0 Angstroms
Exception message:
Attempted to evaluate energy at a = -1.0 Angstroms and c = -1.632993161855452 Angstroms; the model cutoff was estimated to be 9.906790000200273 Angstroms.  This may mean that the model does not possess close-range repulsive forces to prevent system collapse.  In order to prevent possible neighbor list overflow, both a and c must be greater than 0.1 times the model cutoff...
Continuing...


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


Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 3.532158046237435 = ([1.30639453] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 70
         Function evaluations: 150
Results for this minimization:
  a = 2.703727317892886, c = 4.415256250454423, total energy = -63.304757497925976

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 3.7529179241272748 = ([1.38804419] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 70
         Function evaluations: 154
Results for this minimization:
  a = 2.703727301766575, c = 4.415256224877574, total energy = -63.304757497925934

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 3.9736778020171144 = ([1.46969385] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 70
         Function evaluations: 155
Results for this minimization:
  a = 2.703727312681592, c = 4.415256273769437, total energy = -63.30475749792587

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 4.1944376799069545 = ([1.5513435] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 66
         Function evaluations: 145
Results for this minimization:
  a = 2.703727311428529, c = 4.415256357773247, total energy = -63.30475749792579

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 4.415197557796794 = ([1.63299316] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 68
         Function evaluations: 149
Results for this minimization:
  a = 2.703727311788541, c = 4.415256306452683, total energy = -63.304757497925706

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 4.635957435686633 = ([1.71464282] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 77
         Function evaluations: 162
Results for this minimization:
  a = 2.70372730290749, c = 4.415256206084828, total energy = -63.30475749792587

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 4.856717313576473 = ([1.79629248] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 72
         Function evaluations: 155
Results for this minimization:
  a = 2.703727317220238, c = 4.415256260246161, total energy = -63.3047574979257

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 5.077477191466313 = ([1.87794214] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 72
         Function evaluations: 154
Results for this minimization:
  a = 2.7037273259546826, c = 4.415256252585141, total energy = -63.304757497925834

Attempting to perform relaxation using initial lattice constant guess of a = [2.70374528] Angstroms and c = 5.298237069356152 = ([1.95959179] * a) Angstroms

Optimization terminated successfully.
         Current function value: -63.304757
         Iterations: 77
         Function evaluations: 161
Results for this minimization:
  a = 2.703727318980452, c = 4.415256269801171, total energy = -63.3047574979259

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

 Final lattice Constants:
   a = 2.703727317892886 Angstroms, c = 4.415256250454423 Angstroms, c/a = 1.633026

 Total energy: -63.304757497925976 eV

 Cohesive energy: -15.826189374481494 eV/atom

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