def test_get_compliance_expansion(self):
ce_exp = self.exp_cu.get_compliance_expansion()
et_comp = ElasticTensorExpansion(ce_exp)
strain_orig = Strain.from_voigt([0.01, 0, 0, 0, 0, 0])
stress = self.exp_cu.calculate_stress(strain_orig)
strain_revert = et_comp.calculate_stress(stress)
self.assertArrayAlmostEqual(strain_orig, strain_revert, decimal=4)
def test_get_compliance_expansion(self):
ce_exp = self.exp_cu.get_compliance_expansion()
et_comp = ElasticTensorExpansion(ce_exp)
strain_orig = Strain.from_voigt([0.01, 0, 0, 0, 0, 0])
stress = self.exp_cu.calculate_stress(strain_orig)
strain_revert = et_comp.calculate_stress(stress)
self.assertArrayAlmostEqual(strain_orig, strain_revert, decimal=4)
class ElasticTensorExpansionTest(PymatgenTest):
def setUp(self):
with open(os.path.join(test_dir, 'test_toec_data.json')) as f:
self.data_dict = json.load(f)
self.strains = [Strain(sm) for sm in self.data_dict['strains']]
self.pk_stresses = [Stress(d) for d in self.data_dict['pk_stresses']]
self.c2 = self.data_dict["C2_raw"]
self.c3 = self.data_dict["C3_raw"]
self.exp = ElasticTensorExpansion.from_voigt([self.c2, self.c3])
self.cu = Structure.from_spacegroup("Fm-3m", Lattice.cubic(3.623),
["Cu"], [[0] * 3])
indices = [(0, 0), (0, 1), (3, 3)]
values = [167.8, 113.5, 74.5]
cu_c2 = ElasticTensor.from_values_indices(values,
indices,
structure=self.cu,
populate=True)
indices = [(0, 0, 0), (0, 0, 1), (0, 1, 2), (0, 3, 3), (0, 5, 5),
(3, 4, 5)]
values = [-1507., -965., -71., -7., -901., 45.]
cu_c3 = Tensor.from_values_indices(values,
indices,
structure=self.cu,
populate=True)
self.exp_cu = ElasticTensorExpansion([cu_c2, cu_c3])
cu_c4 = Tensor.from_voigt(self.data_dict["Cu_fourth_order"])
self.exp_cu_4 = ElasticTensorExpansion([cu_c2, cu_c3, cu_c4])
warnings.simplefilter("ignore")
def tearDown(self):
warnings.simplefilter("default")
def test_init(self):
cijkl = Tensor.from_voigt(self.c2)
cijklmn = Tensor.from_voigt(self.c3)
exp = ElasticTensorExpansion([cijkl, cijklmn])
from_voigt = ElasticTensorExpansion.from_voigt([self.c2, self.c3])
self.assertEqual(exp.order, 3)
def test_from_diff_fit(self):
exp = ElasticTensorExpansion.from_diff_fit(self.strains,
self.pk_stresses)
def test_calculate_stress(self):
calc_stress = self.exp.calculate_stress(self.strains[0])
self.assertArrayAlmostEqual(self.pk_stresses[0],
calc_stress,
decimal=2)
def test_energy_density(self):
edensity = self.exp.energy_density(self.strains[0])
self.assertAlmostEqual(edensity, 1.36363099e-4)
def test_gruneisen(self):
# Get GGT
ggt = self.exp_cu.get_ggt([1, 0, 0], [0, 1, 0])
self.assertArrayAlmostEqual(
np.eye(3) * np.array([4.92080537, 4.2852349, -0.7147651]), ggt)
# Get TGT
tgt = self.exp_cu.get_tgt()
self.assertArrayAlmostEqual(tgt, np.eye(3) * 2.59631832)
# Get heat capacity
c0 = self.exp_cu.get_heat_capacity(0, self.cu, [1, 0, 0], [0, 1, 0])
self.assertEqual(c0, 0.0)
c = self.exp_cu.get_heat_capacity(300, self.cu, [1, 0, 0], [0, 1, 0])
self.assertAlmostEqual(c, 8.285611958)
# Get Gruneisen parameter
gp = self.exp_cu.get_gruneisen_parameter()
self.assertAlmostEqual(gp, 2.59631832)
gpt = self.exp_cu.get_gruneisen_parameter(temperature=200,
structure=self.cu)
def test_thermal_expansion_coeff(self):
#TODO get rid of duplicates
alpha_dp = self.exp_cu.thermal_expansion_coeff(self.cu,
300,
mode="dulong-petit")
alpha_debye = self.exp_cu.thermal_expansion_coeff(self.cu,
300,
mode="debye")
alpha_comp = 5.9435148e-7 * np.ones((3, 3))
alpha_comp[np.diag_indices(3)] = 21.4533472e-06
self.assertArrayAlmostEqual(alpha_comp, alpha_debye)
def test_get_compliance_expansion(self):
ce_exp = self.exp_cu.get_compliance_expansion()
et_comp = ElasticTensorExpansion(ce_exp)
strain_orig = Strain.from_voigt([0.01, 0, 0, 0, 0, 0])
stress = self.exp_cu.calculate_stress(strain_orig)
strain_revert = et_comp.calculate_stress(stress)
self.assertArrayAlmostEqual(strain_orig, strain_revert, decimal=4)
def test_get_effective_ecs(self):
# Ensure zero strain is same as SOEC
test_zero = self.exp_cu.get_effective_ecs(np.zeros((3, 3)))
self.assertArrayAlmostEqual(test_zero, self.exp_cu[0])
s = np.zeros((3, 3))
s[0, 0] = 0.02
test_2percent = self.exp_cu.get_effective_ecs(s)
diff = test_2percent - test_zero
self.assertArrayAlmostEqual(self.exp_cu[1].einsum_sequence([s]), diff)
def test_get_strain_from_stress(self):
strain = Strain.from_voigt([0.05, 0, 0, 0, 0, 0])
stress3 = self.exp_cu.calculate_stress(strain)
strain_revert3 = self.exp_cu.get_strain_from_stress(stress3)
self.assertArrayAlmostEqual(strain, strain_revert3, decimal=2)
# fourth order
stress4 = self.exp_cu_4.calculate_stress(strain)
strain_revert4 = self.exp_cu_4.get_strain_from_stress(stress4)
self.assertArrayAlmostEqual(strain, strain_revert4, decimal=2)
def test_get_yield_stress(self):
ys = self.exp_cu_4.get_yield_stress([1, 0, 0])
class ElasticTensorExpansionTest(PymatgenTest):
def setUp(self):
with open(os.path.join(test_dir, 'test_toec_data.json')) as f:
self.data_dict = json.load(f)
self.strains = [Strain(sm) for sm in self.data_dict['strains']]
self.pk_stresses = [Stress(d) for d in self.data_dict['pk_stresses']]
self.c2 = self.data_dict["C2_raw"]
self.c3 = self.data_dict["C3_raw"]
self.exp = ElasticTensorExpansion.from_voigt([self.c2, self.c3])
self.cu = Structure.from_spacegroup("Fm-3m", Lattice.cubic(3.623),
["Cu"], [[0]*3])
indices = [(0, 0), (0, 1), (3, 3)]
values = [167.8, 113.5, 74.5]
cu_c2 = ElasticTensor.from_values_indices(values, indices, structure=self.cu,
populate=True)
indices = [(0, 0, 0), (0, 0, 1), (0, 1, 2),
(0, 3, 3), (0, 5, 5), (3, 4, 5)]
values = [-1507., -965., -71., -7., -901., 45.]
cu_c3 = Tensor.from_values_indices(values, indices, structure=self.cu,
populate=True)
self.exp_cu = ElasticTensorExpansion([cu_c2, cu_c3])
cu_c4 = Tensor.from_voigt(self.data_dict["Cu_fourth_order"])
self.exp_cu_4 = ElasticTensorExpansion([cu_c2, cu_c3, cu_c4])
warnings.simplefilter("ignore")
def tearDown(self):
warnings.resetwarnings()
def test_init(self):
cijkl = Tensor.from_voigt(self.c2)
cijklmn = Tensor.from_voigt(self.c3)
exp = ElasticTensorExpansion([cijkl, cijklmn])
from_voigt = ElasticTensorExpansion.from_voigt([self.c2, self.c3])
self.assertEqual(exp.order, 3)
def test_from_diff_fit(self):
exp = ElasticTensorExpansion.from_diff_fit(self.strains, self.pk_stresses)
def test_calculate_stress(self):
calc_stress = self.exp.calculate_stress(self.strains[0])
self.assertArrayAlmostEqual(self.pk_stresses[0], calc_stress, decimal=2)
def test_energy_density(self):
edensity = self.exp.energy_density(self.strains[0])
self.assertAlmostEqual(edensity, 1.36363099e-4)
def test_gruneisen(self):
# Get GGT
ggt = self.exp_cu.get_ggt([1, 0, 0], [0, 1, 0])
self.assertArrayAlmostEqual(
np.eye(3)*np.array([4.92080537, 4.2852349, -0.7147651]), ggt)
# Get TGT
tgt = self.exp_cu.get_tgt()
self.assertArrayAlmostEqual(tgt, np.eye(3)*2.59631832)
# Get heat capacity
c0 = self.exp_cu.get_heat_capacity(0, self.cu, [1, 0, 0], [0, 1, 0])
self.assertEqual(c0, 0.0)
c = self.exp_cu.get_heat_capacity(300, self.cu, [1, 0, 0], [0, 1, 0])
self.assertAlmostEqual(c, 8.285611958)
# Get Gruneisen parameter
gp = self.exp_cu.get_gruneisen_parameter()
self.assertAlmostEqual(gp, 2.59631832)
gpt = self.exp_cu.get_gruneisen_parameter(temperature=200, structure=self.cu)
def test_thermal_expansion_coeff(self):
#TODO get rid of duplicates
alpha_dp = self.exp_cu.thermal_expansion_coeff(self.cu, 300,
mode="dulong-petit")
alpha_debye = self.exp_cu.thermal_expansion_coeff(self.cu, 300,
mode="debye")
alpha_comp = 5.9435148e-7 * np.ones((3, 3))
alpha_comp[np.diag_indices(3)] = 21.4533472e-06
self.assertArrayAlmostEqual(alpha_comp, alpha_debye)
def test_get_compliance_expansion(self):
ce_exp = self.exp_cu.get_compliance_expansion()
et_comp = ElasticTensorExpansion(ce_exp)
strain_orig = Strain.from_voigt([0.01, 0, 0, 0, 0, 0])
stress = self.exp_cu.calculate_stress(strain_orig)
strain_revert = et_comp.calculate_stress(stress)
self.assertArrayAlmostEqual(strain_orig, strain_revert, decimal=4)
def test_get_effective_ecs(self):
# Ensure zero strain is same as SOEC
test_zero = self.exp_cu.get_effective_ecs(np.zeros((3, 3)))
self.assertArrayAlmostEqual(test_zero, self.exp_cu[0])
s = np.zeros((3, 3))
s[0, 0] = 0.02
test_2percent = self.exp_cu.get_effective_ecs(s)
diff = test_2percent - test_zero
self.assertArrayAlmostEqual(self.exp_cu[1].einsum_sequence([s]), diff)
def test_get_strain_from_stress(self):
strain = Strain.from_voigt([0.05, 0, 0, 0, 0, 0])
stress3 = self.exp_cu.calculate_stress(strain)
strain_revert3 = self.exp_cu.get_strain_from_stress(stress3)
self.assertArrayAlmostEqual(strain, strain_revert3, decimal=2)
# fourth order
stress4 = self.exp_cu_4.calculate_stress(strain)
strain_revert4 = self.exp_cu_4.get_strain_from_stress(stress4)
self.assertArrayAlmostEqual(strain, strain_revert4, decimal=2)
def test_get_yield_stress(self):
ys = self.exp_cu_4.get_yield_stress([1, 0, 0])