Efficient First-Principles Approach with a Pseudohybrid Density Functional for Extended Hubbard Interactions

TL;DR

This paper introduces an ab initio method extending DFT+U to include inter-site interactions, achieving accurate band gaps efficiently for solids and surfaces, suitable for large-scale calculations.

Contribution

The paper develops a pseudohybrid functional for DFT+U that self-consistently evaluates inter-site Hubbard interactions, improving band gap predictions with standard DFT computational cost.

Findings

Accurately predicts band gaps comparable to GW and hybrid functionals.

Successfully applied to bulk materials, layered black phosphorous, and surfaces.

Demonstrates suitability for high-throughput and large-scale calculations.

Abstract

For fast and accurate calculations of band gaps of solids, we present an {\it ab initio} method that extends the density functional theory plus on-site Hubbard interaction (DFT+$U$) to include inter-site Hubbard interaction ($V$). This formalism is appropriate for considering various interactions such as a local Coulomb repulsion, covalent hybridizations, and their coexistence in solids. To achieve self-consistent evaluations of $U$ and $V$, we adapt a recently proposed Agapito-Curtarolo-Buongiorno Nardelli pseudohybrid functional for DFT$+U$ to implement a density functional of $V$ and obtain band gaps of diverse bulk materials as accurate as those from $GW$ or hybrid functionals methods with a standard DFT computational cost. Moreover, we also show that computed band gaps of few layers black phosphorous and Si(111)-($2\times1$) surface agree with experiments very well, thus meriting the new method for large-scale as well as high throughput calculations with higher accuracy.