Combining Density Functional Theory and Density Matrix Functional Theory

TL;DR

This paper introduces a hybrid computational method combining density functional theory and density matrix functional theory via range separation, effectively capturing electron correlation with accuracy comparable to standard methods.

Contribution

It presents a novel approach that combines short-range DFT with long-range density matrix functional theory using range separation, improving accuracy in electron correlation calculations.

Findings

Accurately describes static and dynamic electron correlation.

Effective for dissociation curves of small molecules.

Computational cost similar to standard density-functional approximations.

Abstract

We combine density-functional theory with density-matrix functional theory to get the best of both worlds. This is achieved by range separation of the electronic interaction which permits to rigorously combine a short-range density functional with a long-range density-matrix functional. The short-range density functional is approximated by the short-range version of the Perdew-Burke-Ernzerhof functional (srPBE). The long-range density-matrix functional is approximated by the long-range version of the Buijse-Baerends functional (lrBB). The obtained srPBE+lrBB method accurately describes both static and dynamic electron correlation at a computational cost similar to that of standard density-functional approximations. This is shown for the dissociation curves of the H$_{2}$, LiH, BH and HF molecules.