Ab initio Wannier-function-based many-body approach to Born charge of crystalline insulators

TL;DR

This paper introduces a real-space, Wannier-function-based many-body method to compute Born-effective charges in crystalline insulators, incorporating electron-correlation effects for improved accuracy.

Contribution

The paper presents a novel real-space approach using Wannier functions and a Bethe-Goldstone-like hierarchy to include electron correlations in Born charge calculations.

Findings

Method shows promising results for correlation effects

Approach effectively incorporates virtual excitations

Potential for improved accuracy in dielectric properties

Abstract

In this paper we present an approach aimed at performing many-body calculations of Born-effective charges of crystalline insulators, by including the electron-correlation effects. The scheme is implemented entirely in the real space, using Wannier-functions as single-particle orbitals. Correlation effects are computed by including virtual excitations from the Hartree-Fock mean field, and the excitations are organized as per a Bethe-Goldstone-like many-body hierarchy. The results of our calculations suggest that the approach presented here is promising.