Improved Band Gaps and Structural Properties from Wannier-Fermi-L\"{o}wdin Self-Interaction Corrections for Periodic Systems

TL;DR

This paper introduces a new Wannier-Fermi-Löwdin self-interaction correction method for periodic systems that improves band gap and structural property predictions efficiently, outperforming traditional functionals.

Contribution

The paper presents a variational Wannier-Fermi-Löwdin approach for self-interaction correction that is more computationally efficient and yields better results than existing methods.

Findings

Improved band gaps for various materials.

Enhanced bulk moduli accuracy.

Reduced self-interaction errors in calculations.

Abstract

The accurate prediction of band gaps and structural properties in periodic systems continues to be one of the central goals of electronic structure theory. However, band gaps obtained from popular exchange-correlation functionals (such as LDA and PBE) are severely underestimated partly due to the spurious self-interaction error (SIE) inherent to these functionals. In this work, we present a new formulation and implementation of Wannier function-derived Fermi-L\"{o}wdin (WFL) orbitals for correcting the SIE in periodic systems. Since our approach utilizes a variational minimization of the self-interaction energy with respect to the Wannier charge centers, it is computationally more efficient than the HSE hybrid functional and other self-interaction corrections that require a large number of transformation matrix elements. Calculations on several (17 in total) prototypical molecular solids, semiconductors, and wide-bandgap materials show that our WFL self-interaction correction approach gives better band gaps and bulk moduli compared to semilocal functionals, largely due to the partial removal of self-interaction errors.