Dielectric screening in extended systems using the self-consistent Sternheimer equation and localized basis sets

TL;DR

This paper introduces a first-principles computational method for dielectric screening in extended systems that avoids calculating unoccupied states, using localized basis sets and the self-consistent Sternheimer equation, with accuracy comparable to planewaves methods.

Contribution

The authors develop a novel approach combining the Sternheimer equation with localized basis sets, eliminating the need for unoccupied state calculations in dielectric screening computations.

Findings

Method achieves accuracy comparable to planewaves calculations.

Systematic basis set optimization enhances precision.

Computational scaling is order O(N^3).

Abstract

We develop a first-principles computational method for investigating the dielectric screening in extended systems using the self-consistent Sternheimer equation and localized non-orthogonal basis sets. Our approach does not require the explicit calculation of unoccupied electronic states, only uses two-center integrals, and has a theoretical scaling of order O(N^3). We demonstrate this method by comparing our calculations for silicon, germanium, diamond, and LiCl with reference planewaves calculations. We show that accuracy comparable to planewaves calculations can be achieved via a systematic optimization of the basis set.