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First-principles perturbative computation of dielectric and Born charge tensors in finite electric fields

Xinjie Wang·David Vanderbilt
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Abstract

We present a perturbative treatment of the response properties of insulating crystals under a dc bias field, and use this to study the effects of such bias fields on the Born effective charge tensor and dielectric tensor of insulators. We start out by expanding a variational field-dependent total-energy functional with respect to the electric field within the framework of density-functional perturbation theory. The second-order term in the expansion of the total energy is then minimized with respect to the first-order wave functions, from which the Born effective charge tensor and dielectric tensor are easily computed. We demonstrate an implementation of the method and perform illustrative calculations for the III-V semiconductors AlAs and GaAs under finite bias field.

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Xinjie Wang, David Vanderbilt. 2006-12-17. First-principles perturbative computation of dielectric and Born charge tensors in finite electric fields. https://doi.org/10.1103/physrevb.75.115116

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