Energy functionals of single-particle densities: A unified view

TL;DR

This paper presents a unified second-quantized framework for density functional theory that treats all single-particle contributions to energy exactly, extending the traditional density-based approach to include momentum and other densities.

Contribution

It introduces a comprehensive second-quantized approach to density functional theory that unifies various density functionals and treats all single-particle energies exactly.

Findings

Unified second-quantized framework for density functionals

Exact treatment of all single-particle contributions

Extension to momentum-space and other densities

Abstract

Density functional theory is usually formulated in terms of the density in configuration space. Functionals of the momentum-space density have also been studied, and yet other densities could be considered. We offer a unified view from a second-quantized perspective and introduce a version of density functional theory that treats all single-particle contributions to the energy exactly. An appendix deals with semiclassical eigenvalues.