Quantum Monte Carlo study of MnO solid

TL;DR

This paper uses quantum Monte Carlo methods to accurately study the electronic structure of MnO, highlighting the importance of electron correlation and exact exchange in modeling transition metal oxides.

Contribution

It introduces a QMC approach with trial wavefunctions from Hartree-Fock and DFT, providing improved estimates of electronic properties of MnO.

Findings

QMC estimates of the gap and cohesion agree well with experiments

Correlation effects are significant in MnO

Exact exchange improves DFT descriptions of transition metal oxides

Abstract

Electronic structure of the manganese oxide solid is studied by the quantum Monte Carlo (QMC) methods. The trial wavefunctions are built using orbitals from unrestricted Hartree-Fock and Density Functional Theory, and the electron-electron correlation is recovered by the fixed-node QMC. The correlation effects are significant and QMC estimations of the gap and cohesion show a very good agreement with experiment. Comparison with hybrid functional results points out the importance of the exact exchange for improvement of the Density Functional description of transition metal oxide systems.