Toward an all-round semi-local potential for the electronic exchange

TL;DR

This paper evaluates a semi-local exchange potential in density functional theory across various systems, demonstrating its accuracy and computational efficiency, and proposing it as a promising universal approximation.

Contribution

It introduces and tests a universal semi-local exchange potential combining a recent extension with a classical approximation, showing its broad applicability and accuracy.

Findings

Good agreement with experimental and exact results

Moderate computational cost

Potential as a universal semi-local exchange functional

Abstract

We test local and semi-local density functionals for the electronic exchange for a variety of systems including atoms, molecules, and atomic chains. In particular, we focus on a recent universal extension of the Becke-Johnson exchange potential [E. R\"as\"anen, S. Pittalis, and C. R. Proetto, J. Chem. Phys. 132, 044112 (2010)]. It is shown that when this potential is used together with the Becke-Roussel approximation to the Slater potential [A. D. Becke and M. R. Roussel, Phys. Rev. A 39, 3761 (1989)], a good overall agreement is obtained with experimental and numerically exact results for several systems, and with a moderate computational cost. Thus, this approximation is a very promising candidate in the quest for a simple and all-round semi-local potential.