$GW$ self-screening error and its correction using a local density functional

TL;DR

This paper introduces a computationally efficient local density functional correction for $GW$ calculations that effectively eliminates self-screening errors, improving electron density and ionization potential accuracy.

Contribution

A novel local density functional correction for $GW$ methods that reduces self-screening errors in electronic structure calculations.

Findings

Eliminates self-screening errors in electron density.

Improves accuracy of ionization potential calculations.

Efficient correction applicable to various systems.

Abstract

The self-screening error in electronic structure theory is the part of the self-interaction error that would remain within the $GW$ approximation if the exact dynamically screened Coulomb interaction, $W$, were used, causing each electron to artificially screen its own presence. This introduces error into the electron density and ionization potential. We propose a simple, computationally efficient correction to $GW$ calculations in the form of a local density functional, obtained using a series of finite training systems; in tests, this eliminates the self-screening errors in the electron density and ionization potential.