The charge density of semiconductors in the GW approximation

TL;DR

This paper introduces a method to compute the electronic charge density of semiconductors within the GW approximation, demonstrating charge conservation and good agreement with experimental data for silicon and germanium.

Contribution

The paper develops a space-time method for charge density calculation in GW approximation and assesses charge conservation and accuracy against experimental values.

Findings

GW charge density closely matches experimental data

Charge is effectively conserved in the GW approximation

Using LDA Hartree potential is justified for quasi-particle energies

Abstract

We present a method to calculate the electronic charge density of periodic solids in the GW approximation, using the space-time method. We investigate for the examples of silicon and germanium to what extent the GW approximation is charge-conserving and how the charge density compares with experimental values. We find that the GW charge density is close to experiment and charge is practically conserved. We also discuss how using a Hartree potential consistent with the level of approximation affects the quasi-particle energies and find that the common simplification of using the LDA Hartree potential is a very well justified.