Adiabatic-connection fluctuation-dissipation density-functional theory based on range separation

TL;DR

This paper introduces a new density-functional theory approach combining short-range functionals with long-range RPA to better describe weakly-bound systems like van der Waals dimers, improving accuracy over standard methods.

Contribution

It proposes a novel adiabatic-connection fluctuation-dissipation method based on range separation, enhancing the description of weakly-bound systems.

Findings

Improved description of van der Waals dimers Be₂ and Ne₂.

Corrects shortcomings of standard RPA.

Effective for weakly-bound systems.

Abstract

An adiabatic-connection fluctuation-dissipation theorem approach based on a range separation of electron-electron interactions is proposed. It involves a rigorous combination of short-range density functional and long-range random phase approximations. This method corrects several shortcomings of the standard random phase approximation and it is particularly well suited for describing weakly-bound van der Waals systems, as demonstrated on the challenging cases of the dimers Be$_2$ and Ne$_2$.