Local modified Becke-Johnson exchange-correlation potential for interfaces, surfaces, and two-dimensional materials

TL;DR

This paper introduces a local extension of the modified Becke-Johnson potential in density functional theory, enabling accurate and efficient electronic structure calculations for heterogeneous, finite, and low-dimensional systems such as interfaces and surfaces.

Contribution

It proposes a coordinate-dependent parameter c for the Becke-Johnson potential, allowing its application to non-periodic and nanostructured systems while maintaining accuracy and computational efficiency.

Findings

Accurately predicts band gaps in various systems.

Provides band diagrams and offsets from a single calculation.

Effective for interfaces, surfaces, and 2D materials.

Abstract

The modified Becke-Johnson meta-GGA potential of density functional theory has been shown to be the best exchange-correlation potential to determine band gaps of crystalline solids. However, it cannot be consistently used for the electronic structure of non-periodic or nanostructured systems. We propose an extension of this potential that enables its use to study heterogeneous, finite and low-dimensional systems. This is achieved by using a coordinate-dependent expression for the parameter $c$ that weights the Becke-Russel exchange, in contrast to the original global formulation, where $c$ is just a fitted number. Our potential takes advantage of the excellent description of band gaps provided by the modified Becke-Johnson potential and preserves its modest computational effort. Furthermore, it yields with one single calculation band diagrams and band offsets of heterostructures and surfaces. We exemplify the usefulness and efficiency of our local meta-GGA potential by testing it for a series of interfaces (Si/SiO$_2$, AlAs/GaAs, AlP/GaP, and GaP/Si), a Si surface, and boron nitride monolayer.