Finite-size correction in many-body electronic structure calculations

TL;DR

This paper introduces a simple post-processing method to correct finite-size errors in many-body electronic structure calculations, significantly improving accuracy for insulators, semiconductors, and metals.

Contribution

A new parametrization of the finite-size exchange-correlation functional enables effective correction of finite-size effects in many-body calculations.

Findings

Significantly improved finite-size corrections for P$_2$ in a supercell

Enhanced accuracy in semiconducting Si calculations

Effective correction method for metallic Na

Abstract

Finite-size (FS) effects are a major source of error in many-body (MB) electronic structure calculations of extended systems. A method is presented to correct for such errors. We show that MB FS effects can be effectively included in a modified local density approximation calculation. A parametrization for the FS exchange-correlation functional is obtained. The method is simple and gives post-processing corrections that can be applied to any MB results. Applications to a model insulator (P$_2$ in a supercell), to semiconducting Si, and to metallic Na show that the method delivers greatly improved FS corrections.