A local Fock-exchange potential in Kohn-Sham equations

TL;DR

This paper introduces a local Fock-exchange potential for Kohn-Sham equations that closely approximates the exact exchange potential, enabling accurate electronic structure calculations for complex systems.

Contribution

The authors derive a new local Fock-exchange potential that improves upon existing methods by providing robustness and accuracy in systems where traditional approaches struggle.

Findings

Accurately models exchange interactions in diverse materials

Performs well in systems traditionally considered challenging

Provides a practical implementation compatible with existing software

Abstract

We derive and employ a local potential to represent the Fock exchange operator in electronic single-particle equations. This local Fock-exchange (LFX) potential is very similar to the exact exchange (EXX) potential in density functional theory (DFT). The practical software implementation of the two potentials (LFX and EXX) yields robust and accurate results for a variety of systems (semiconductors, transition metal oxides) where Hartree Fock and popular approximations of DFT typically fail. This includes examples traditionally considered qualitatively inaccessible to calculations that omit correlation.