Towards improved exact exchange functionals relying on GW quasiparticle methods for parametrization

TL;DR

This paper develops a modified exchange functional based on GW calculations that improves band structure predictions for semiconductors and insulators with lower computational costs, while discussing its limitations in low-dimensional systems.

Contribution

The paper introduces a new parametrization of the HSE functional using GW data, enhancing accuracy and efficiency in band structure calculations for bulk materials.

Findings

Accurately predicts band structures of bulk Si, Ge, GaAs, and CdTe.

Reduces computational cost compared to GW methods.

Shows limitations in low-dimensional systems like 2D materials and nanotubes.

Abstract

We use fully self-consistent GW calculations on diamond and silicon carbide to reparametrize the Heyd-Scuseria-Ernzerhof exact exchange density functional for use in band structure calculations of semiconductors and insulators. We show that the thus modified functional is able to calculate the band structure of bulk Si, Ge, GaAs, and CdTe with good quantitative accuracy at a significantly reduced computational cost as compared to GW methods. We discuss the limitations of this functional in low-dimensions by calculating the band structures of single-layer hexagonal BN and MoS$_{2}$, and by demonstrating that the diameter scaling of curvature induced band gaps in single-walled carbon nanotubes is still physically incorrect using our functional; we consider possible remedies to this problem.