Nonlocal Orbital-Free kinetic pressure tensors for the Fermi gas

TL;DR

This paper introduces a new nonlocal density functional for the kinetic pressure tensor in Fermi gases, bridging quantum hydrodynamics and microscopic models, and demonstrates its superior accuracy through systematic testing.

Contribution

A novel nonlocal functional for the kinetic pressure tensor that improves the modeling of Fermi gases and small sodium clusters.

Findings

Quantitatively superior to existing functionals

Effective in both equilibrium and dynamical regimes

Applicable to small sodium clusters

Abstract

A novel nonlocal density functional for the kinetic pressure tensor of a Fermi gas is derived. The functional is designed to reconcile the Quantum Hydrodynamic Model with the microscopic approaches, both for homogeneous equilibrium and dynamical regime. The derivation opens new ways to improve and implement further time-nonlocal functionals. The present proposal is systematically tested in and beyond the linear regime for the Fermi gas, as well as for some small sodium clusters, proving that it is quantitative superior to other existing functionals.