Semilocal Pauli-Gaussian Kinetic Functionals for Orbital-Free Density Functional Theory Calculations of Solids

TL;DR

This paper demonstrates that well-designed semilocal Pauli-Gaussian kinetic energy functionals, especially at the Laplacian level, can rival non-local functionals in accuracy for orbital-free density functional theory of solids, eliminating the need for system-dependent parameters.

Contribution

It introduces and validates semilocal Pauli-Gaussian KE functionals at the Laplacian level as accurate alternatives to non-local functionals for solids.

Findings

Semilocal PG KE functionals achieve comparable accuracy to non-local functionals.

Laplacian-level PG functionals perform well for metals and semiconductors.

No system-dependent parameters are needed for accurate results.

Abstract

Kinetic energy (KE) approximations are key elements in orbital-free density functional theory. To date, the use of non-local functionals, possibly employing system dependent parameters, has been considered mandatory in order to obtain satisfactory accuracy for different solid-state systems, whereas semilocal approximations are generally regarded as unfit to this aim. Here, we show that instead properly constructed semilocal approximations, the Pauli-Gaussian (PG) KE functionals, especially at the Laplacian-level of theory, can indeed achieve similar accuracy as non-local functionals and can be accurate for both metals and semiconductors, without the need of system-dependent parameters.