A non-local exchange potential for electronic structure calculations

TL;DR

This paper introduces a new non-local exchange potential model for electronic structure calculations that improves accuracy over local-density approximations by correctly capturing long-range behavior, applicable to atoms, molecules, and solids.

Contribution

It presents a simple, physically motivated scheme for exchange potential calculation that aligns with Hartree-Fock theory and improves upon existing local approximations.

Findings

Accurately reproduces asymptotic long-range behavior of exchange potential.

Provides results close to Kohn-Sham calculations in solid interstitials.

Achieves good agreement with experimental data for atomic energies.

Abstract

In this work we describe a model for the exchange interaction of electrons, as it follows from the Pauli exclusion principle. Starting from Hartree-Fock theory and making use of the free electron-gas model we propose a simple scheme to calculate the exchange-potential for atoms as well as simple molecules and solids. This method assures the correct asymptotic long-range behavior of the potential, contrary to local-density approximations that rely on a strongly simplified generalization of the well-known Kohn-Sham or Slater exchange interaction. Furthermore, our results approach the Kohn-Sham results in the interstitial space of solids. As a benchmark test, total energies and eigenenergies for atoms from He to Xe computed within our model are compared to other calculations as well as to experimental data.