Reduced Density Matrix Functional for Many-Electron Systems

TL;DR

This paper introduces a new reduced density matrix functional tailored for solids, improving accuracy in finite systems and correctly predicting band gaps in semiconductors and Mott insulators without magnetic order.

Contribution

A novel exchange correlation functional based on fractional powers of the density matrix is proposed, enhancing predictive capabilities for diverse electronic systems.

Findings

More accurate results for finite systems.

Correct band gap predictions for semiconductors.

Effective in strongly correlated Mott insulators.

Abstract

Reduced density matrix functional theory for the case of solids is presented and a new exchange correlation functional based on a fractional power of the density matrix is introduced. We show that compared to other functionals, this produces more accurate results for both finite systems. Moreover, it captures the correct band gap behavior for conventional semiconductors as well as strongly correlated Mott insulators, where a gap is obtained in absence of any magnetic ordering.