Non-empirical Generalized Gradient Approximation Free Energy Functional for Orbital-free Simulations

TL;DR

This paper introduces a novel non-empirical generalized gradient approximation free energy functional for orbital-free density functional theory, enabling efficient and accurate molecular dynamics simulations in warm dense matter conditions.

Contribution

It presents the first wholly non-empirical GGA free energy functional for orbital-free DFT, improving simulation efficiency and accuracy in WDM regimes.

Findings

Good agreement with Kohn-Sham calculations

Significantly reduced computational cost

Effective for finite-temperature molecular dynamics

Abstract

We report the first wholly non-empirical generalized gradient approximation, non-interacting free energy functional for orbital-free density functional theory and use that new functional to provide forces for finite-temperature molecular dynamics simulations in the warm dense matter (WDM) regime The new functional provides good-to-excellent agreement with reference Kohn-Sham calculations under WDM conditions at a minuscule fraction of the computational cost of corresponding orbital-based simulations.