Pseudopotentials for Orbital-Free DFT: Capturing Nonlocality and Correcting Functional Approximants

TL;DR

This paper introduces a new framework and pseudopotential construction method for orbital-free DFT, significantly improving the accuracy and transferability of pseudopotentials for transition metals, and providing a foundation for future methodological improvements.

Contribution

A theoretical framework and a novel pseudization method for creating local pseudopotentials in OF-DFT, with four new pseudopotential sets tested on transition metals.

Findings

Substantial improvement over previous pseudopotentials.

Four new pseudopotential sets developed and evaluated.

Current OF-DFT functionals remain qualitatively accurate for transition metals.

Abstract

Developing reliable pseudopotentials for orbital-free density functional theory (OF-DFT), especially for transition metals, remains a significant challenge. In this study, we provide a theoretical framework for analyzing pseudization strategies for OF-DFT calculations. From the analysis arises a proposed pseudization method which involves constructing local pseudopotentials by targeting existing Kohn-Sham DFT pseudopotentials through an optimized effective potential procedure. We produce four distinct sets of local pseudopotentials and evaluate their accuracy and transferability on the transition metal elements. Our results indicate a substantial improvement over previously available pseudopotentials. Although current OF-DFT functionals still only reach a qualitative accuracy for transition metals, our newly developed pseudopotentials provide a rigorous framework for further methodological advancements.