Density functional theory for strongly-interacting electrons: Perspectives for Physics and Chemistry

TL;DR

This paper discusses recent advances in density functional theory (DFT), focusing on the strong-interaction limit, and explores how this new understanding can improve practical calculations in physics and chemistry.

Contribution

It introduces the use of the strong-interaction limit of DFT to develop new frameworks and improve exchange-correlation functionals for challenging chemical and physical systems.

Findings

Mathematical structure of the strong-interaction limit has been uncovered.

Exact information on the strong-interaction limit is now available.

Potential for improved DFT calculations in material science and chemistry.

Abstract

Improving the accuracy and thus broadening the applicability of electronic density functional theory (DFT) is crucial to many research areas, from material science, to theoretical chemistry, biophysics and biochemistry. In the last three years, the mathematical structure of the strong-interaction limit of density functional theory has been uncovered, and exact information on this limit has started to become available. The aim of this paper is to give a perspective on how this new piece of exact information can be used to treat situations that are problematic for standard Kohn-Sham DFT. One way to use the strong-interaction limit, more relevant for solid-state physical devices, is to define a new framework to do practical, non-conventional, DFT calculations in which a strong-interacting reference system is used instead of the traditional non-interacting one of Kohn and Sham. Another way to proceed, more related to chemical applications, is to include the exact treatment of the strong-interaction limit into approximate exchange-correlation energy density functionals in order to describe difficult situations such as the breaking of the chemical bond.