Highly Accurate Local Pseudopotentials of Li, Na, and Mg for Orbital Free Density Functional Theory

TL;DR

This paper introduces a method to generate highly accurate pseudopotentials for orbital-free density functional theory, enabling large-scale simulations of materials with improved precision over traditional approaches.

Contribution

The authors develop a novel fitting procedure for pseudopotentials that reduces errors in OF-DFT calculations, validated on Li, Na, and Mg.

Findings

Accurate geometries and energies for Li, Na, and Mg phases.

Reliable vacancy formation and bulk modulus calculations.

Enhanced suitability for large-scale materials simulations.

Abstract

We present a method to make highly accurate pseudopotentials for use with orbital-free density functional theory (OF-DFT) with given exchange-correlation and kinetic energy functionals, which avoids the compounding of errors of Kohn-Sham DFT and OF-DFT. The pseudopotentials are fitted to reference (experimental or highly accurate quantum chemistry) values of interaction energies, geometries, and mechanical properties, using a genetic algorithm. This can enable routine large-scale ab initio simulations of many practically relevant materials. Pseudopotentials for Li, Na, and Mg resulting in accurate geometries and energies of different phases as well as of vacancy formation and bulk moduli are presented as examples.