def test_direct_evaluation(self):
a = FaceCenteredCubic('Au', size=[2,2,2])
a.rattle(0.1)
calc = EAM('Au-Grochola-JCP05.eam.alloy')
a.set_calculator(calc)
f = a.get_forces()
calc2 = EAM('Au-Grochola-JCP05.eam.alloy')
i_n, j_n, dr_nc, abs_dr_n = neighbour_list('ijDd', a, cutoff=calc2.cutoff)
epot, virial, f2 = calc2.energy_virial_and_forces(a.numbers, i_n, j_n, dr_nc, abs_dr_n)
self.assertArrayAlmostEqual(f, f2)
a = FaceCenteredCubic('Cu', size=[2,2,2])
calc = EAM('CuAg.eam.alloy')
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e_Cu = a.get_potential_energy()/len(a)
a = FaceCenteredCubic('Ag', size=[2,2,2])
a.set_calculator(calc)
FIRE(StrainFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e_Ag = a.get_potential_energy()/len(a)
self.assertTrue(abs(e_Ag+2.85)<1e-6)
a = L1_2(['Ag', 'Cu'], size=[2,2,2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e = a.get_potential_energy()
syms = np.array(a.get_chemical_symbols())
self.assertTrue(abs((e-(syms=='Cu').sum()*e_Cu-
(syms=='Ag').sum()*e_Ag)/len(a)-0.096)<0.0005)
a = B1(['Ag', 'Cu'], size=[2,2,2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e = a.get_potential_energy()
syms = np.array(a.get_chemical_symbols())
self.assertTrue(abs((e-(syms=='Cu').sum()*e_Cu-
(syms=='Ag').sum()*e_Ag)/len(a)-0.516)<0.0005)
a = B2(['Ag', 'Cu'], size=[2,2,2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e = a.get_potential_energy()
syms = np.array(a.get_chemical_symbols())
self.assertTrue(abs((e-(syms=='Cu').sum()*e_Cu-
(syms=='Ag').sum()*e_Ag)/len(a)-0.177)<0.0003)
a = L1_2(['Cu', 'Ag'], size=[2,2,2], latticeconstant=4.0)
a.set_calculator(calc)
FIRE(UnitCellFilter(a, mask=[1,1,1,0,0,0]), logfile=None).run(fmax=0.001)
e = a.get_potential_energy()
syms = np.array(a.get_chemical_symbols())
self.assertTrue(abs((e-(syms=='Cu').sum()*e_Cu-
(syms=='Ag').sum()*e_Ag)/len(a)-0.083)<0.0005)
def test_potentiostat():
size = 2
atoms = FaceCenteredCubic(directions=[[1, 0, 0], [0, 1, 0], [0, 0, 1]],
symbol='Al',
size=(size, size, size),
pbc=True)
atoms.set_calculator(EMT())
E0 = atoms.get_potential_energy()
atoms.rattle(stdev=0.18, seed=312)
md_temp = 300
rng = np.random.RandomState(60622)
MaxwellBoltzmannDistribution(atoms, temperature_K=md_temp, rng=rng)
initial_energy = atoms.get_potential_energy()
print("Energy Above Ground State: {: .4f} eV/atom".format(
(initial_energy - E0) / len(atoms)))
name = 'test_potentiostat'
traj_name = name + '.traj'
log_name = name + '.log'
dyn = contour_exploration(
atoms,
maxstep=1.0,
parallel_drift=0.05,
remove_translation=True,
force_parallel_step_scale=None,
energy_target=initial_energy,
angle_limit=20,
use_tangent_curvature=False,
#trajectory = traj_name,
#logfile = log_name,
)
for i in range(5):
dyn.run(10)
energy_error = (atoms.get_potential_energy() -
initial_energy) / len(atoms)
print('Potentiostat Error {: .4f} eV/atom'.format(energy_error))
assert 0 == pytest.approx(energy_error, abs=0.01)
def get_atoms():
atoms = FaceCenteredCubic(directions=[[1,-1,0], [1,1,0], [0,0,1]],
size=(3,3,3), symbol='Cu', pbc=(1,1,1))
atoms.rattle(stdev=0.1,seed=42)
return atoms
