Libxc: a library of exchange and correlation functionals for density functional theory

TL;DR

Libxc is a comprehensive library providing routines to evaluate approximately 180 exchange-correlation functionals and their derivatives, facilitating practical density functional theory calculations.

Contribution

It introduces a unified library of exchange-correlation functionals, covering a wide range of approximations used in density functional theory.

Findings

Supports around 180 functionals and derivatives

Enables consistent and efficient DFT calculations

Facilitates research and development in electronic structure methods

Abstract

The central quantity of density functional theory is the so-called exchange-correlation functional. This quantity encompasses all non-trivial many-body effects of the ground-state and has to be approximated in any practical application of the theory. For the past 50 years, hundreds of such approximations have appeared, with many successfully persisting in the electronic structure community and literature. Here, we present a library that contains routines to evaluate many of these functionals (around 180) and their derivatives.