def expand_raman_by_symmetry(cachepath, phonon, disp_filenames,
get_polarizability, ex_kw,
subtract_equilibrium_polarizability):
if os.path.exists(cachepath):
parprint(f'Found existing {cachepath}')
return np.load(cachepath)
world.barrier()
parprint(f'Expanding raman data by symmetry... ({cachepath})')
disp_phonopy_sites, disp_carts = get_phonopy_displacements(phonon)
prim_symmetry = phonon.primitive_symmetry.get_symmetry_operations()
lattice = phonon.primitive.get_cell()[...]
carts = phonon.primitive.get_positions()
oper_frac_rots = prim_symmetry['rotations']
oper_frac_trans = prim_symmetry['translations']
oper_cart_rots = np.array(
[np.linalg.inv(lattice).T @ R @ lattice.T for R in oper_frac_rots])
oper_cart_trans = oper_frac_trans @ lattice
oper_deperms = []
for cart_rot, cart_trans in zip(oper_cart_rots, oper_cart_trans):
carts = phonon.primitive.get_positions()
transformed_carts = carts @ cart_rot.T + cart_trans
oper_deperms.append(get_deperm(carts, transformed_carts, lattice))
oper_deperms = np.array(oper_deperms)
disp_tensors = np.array([
get_polarizability(
LrTDDFT.read(disp_filenames['ex']['disp'].format(i), **ex_kw))
for i in range(len(disp_phonopy_sites))
])
if subtract_equilibrium_polarizability:
disp_tensors -= get_polarizability(
LrTDDFT.read(disp_filenames['ex']['eq'], **ex_kw))
pol_derivs = symmetry.expand_derivs_by_symmetry(
disp_phonopy_sites,
disp_carts,
disp_tensors,
symmetry.Tensor2Callbacks(),
oper_cart_rots,
oper_deperms,
)
pol_derivs = np.array(
pol_derivs.tolist()) # (n,3) dtype=object --> (n,3,3,3) dtype=complex
np.save(cachepath, pol_derivs)
return pol_derivs
