Local-spin-density functional for multideterminant density functional theory

TL;DR

This paper develops a new local-spin-density functional for multideterminant density functional theory, combining quantum Monte Carlo data and exact limits to better describe electron correlations across different ranges.

Contribution

It introduces an analytic exchange-correlation functional tailored for multideterminantal DFT, integrating long- and short-range electron correlation effects.

Findings

Accurate energy estimates for a modified electron gas with long-range Coulomb interactions.

Construction of a new local-spin-density functional suitable for advanced DFT methods.

Enhanced description of electron correlations in quantum chemistry applications.

Abstract

Based on exact limits and quantum Monte Carlo simulations, we obtain, at any density and spin polarization, an accurate estimate for the energy of a modified homogeneous electron gas where electrons repel each other only with a long-range coulombic tail. This allows us to construct an analytic local-spin-density exchange-correlation functional appropriate to new, multideterminantal versions of the density functional theory, where quantum chemistry and approximate exchange-correlation functionals are combined to optimally describe both long- and short-range electron correlations.