def _get_gv(self, q):
return get_group_velocity(
q,
self._dm,
q_length=self._gv_delta_q,
symmetry=self._symmetry,
frequency_factor_to_THz=self._frequency_factor_to_THz)
def _get_gv(self, q):
return get_group_velocity(
q,
self._dm,
q_length=self._gv_delta_q,
symmetry=self._symmetry,
frequency_factor_to_THz=self._frequency_factor_to_THz)
def _set_gv(self, i):
# Group velocity [num_freqs, 3]
self._gv[i] = get_group_velocity(
self._qpoints[i],
self._dm,
q_length=self._gv_delta_q,
symmetry=self._symmetry,
frequency_factor_to_THz=self._frequency_factor_to_THz)
def get_boundary_scattering_strength(self):
self._set_group_velocity(grid_points=[self._grid_point])
bnd_collision_unit = 100. / 1e-6 / THz / (2 * np.pi) # unit in THz, unit of length is micron
gv = self._gv_all[self._grid_point]
dm = self._pp.get_dynamical_matrix()
gv1 = get_group_velocity(self._qpoint,
dm,
symmetry=self._pp._symmetry,
q_length=self._gv_delta_q,
frequency_factor_to_THz=self._pp.get_frequency_factor_to_THz())
gv_average = np.sqrt(np.sum(gv ** 2, axis=-1))
n = self._occupations_all[self._grid_point, self._itemp]
cout_bnd = gv_average / self._length * n * (n + 1)
return cout_bnd * bnd_collision_unit
def get_boundary_scattering_strength(self):
self._set_group_velocity(grid_points=[self._grid_point])
bnd_collision_unit = 100. / 1e-6 / THz / (
2 * np.pi) # unit in THz, unit of length is micron
gv = self._gv_all[self._grid_point]
dm = self._pp.get_dynamical_matrix()
gv1 = get_group_velocity(
self._qpoint,
dm,
symmetry=self._pp._symmetry,
q_length=self._gv_delta_q,
frequency_factor_to_THz=self._pp.get_frequency_factor_to_THz())
gv_average = np.sqrt(np.sum(gv**2, axis=-1))
n = self._occupations_all[self._grid_point, self._itemp]
cout_bnd = gv_average / self._length * n * (n + 1)
return cout_bnd * bnd_collision_unit
def _set_kappa_at_sigmas(self, i):
freqs = self._frequencies[i]
# Group velocity [num_freqs, 3]
if not self._read_gv:
gv = get_group_velocity(
self._qpoint,
self._dm,
self._symmetry,
q_length=self._gv_delta_q,
frequency_factor_to_THz=self._frequency_factor_to_THz)
self._gv[i] = gv
# self._gv[i] = self._get_degenerate_gv(i)
# Heat capacity [num_temps, num_freqs]
cv = self._get_cv(freqs)
self._cv[i] = cv
num_kstar_counted = False
try:
import anharmonic._phono3py as phono3c
rec_lat = np.linalg.inv(self._primitive.get_cell())
kpt_rotations_at_q = self._get_rotations_for_star(i)
if self._sigma_iteration_step == 0:
self._sum_num_kstar += len(kpt_rotations_at_q)
num_kstar_counted = True
deg = degenerate_sets(self._frequencies[i])
degeneracy = np.zeros(len(self._frequencies[i]), dtype="intc")
for ele in deg:
for sub_ele in ele:
degeneracy[sub_ele]=ele[0]
for j, sigma in enumerate(self._sigmas):
kappa_at_qs = np.zeros_like(self._kappa[j,i])
mfp = np.zeros((len(self._temperatures), self._frequencies.shape[1], 3), dtype="double")
for t, temp in enumerate(self._temperatures):
for k in range(3):
mfp[t,:,k] = np.where(self._gamma[j,i,t] > 0.5 / self._cutoff_lifetime / THz,
self._gv[i,:,k] / self._gamma[j,i,t],
0)
phono3c.thermal_conductivity_at_grid(kappa_at_qs,
kpt_rotations_at_q.astype("intc").copy(),
rec_lat.copy(),
cv.copy(),
mfp.copy(),
self._gv[i].copy(),
degeneracy.copy())
self._kappa[j,i] = kappa_at_qs / 2 * self._conversion_factor
except ImportError:
print "Warning: kappa calculation (the final step) went wrong in the C implementation. Changing to python instead..."
# Outer product of group velocities (v x v) [num_k*, num_freqs, 3, 3]
gv_by_gv_tensor = self._get_gv_by_gv(i)
if self._sigma_iteration_step == 0 and num_kstar_counted == False:
self._sum_num_kstar += len(gv_by_gv_tensor)
# Sum all vxv at k*
gv_sum2 = np.zeros((6, len(freqs)), dtype='double')
for j, vxv in enumerate(
([0, 0], [1, 1], [2, 2], [1, 2], [0, 2], [0, 1])):
gv_sum2[j] = gv_by_gv_tensor[:, :, vxv[0], vxv[1]].sum(axis=0)
# Kappa
for j, sigma in enumerate(self._sigmas):
for k, l in list(np.ndindex(len(self._temperatures), len(freqs))):
if self._gamma[j, i, k, l] < 0.5 / self._cutoff_lifetime / THz:
continue
self._kappa[j, i, k, l, :] = (
gv_sum2[:, l] * cv[k, l] / (self._gamma[j, i, k, l] * 2) *
self._conversion_factor)