PAOFLOW.phonon.do_born_charges#

Born effective charges and high-frequency dielectric tensor (Stage 2b).

The macroscopic Born effective charge tensor and the clamped-ion (electronic) dielectric tensor are obtained from one of two routes:

  • method='dfpt' (default): a single Gamma-point density-functional perturbation theory run (Quantum ESPRESSO ph.x with epsil=.true., trans=.false.) yields both tensors directly. Fast and accurate, but not available for DFT+U / hybrid functionals.

  • method='field': finite electric-field (lelfield) calculations on the primitive cell, with central differences of the per-atom forces (Born charges) and the macroscopic polarization (dielectric tensor). Slower, but works whenever ph.x cannot be used.

The acoustic sum rule (sum_k Z*_k = 0) is imposed and both tensors are symmetrized before the phonopy BORN file is written.

Functions#

compute_born_and_epsilon(data_controller[, method, ...])

Assemble Born charges and epsilon_inf from a DFPT or finite-field run.

Module Contents#

PAOFLOW.phonon.do_born_charges.compute_born_and_epsilon(data_controller, method='dfpt', phonon_dir='phonon', enforce_sum_rule=True, symmetrize=True, write_born=True)[source]#

Assemble Born charges and epsilon_inf from a DFPT or finite-field run.

Returns:

{'born', 'dielectric'} with the Born charges of shape (natom_prim, 3, 3) (units of the elementary charge) and the (3, 3) high-frequency dielectric tensor.

Return type:

dict