Accurate evaluation of magnetic coupling between atoms with numerous open-shells : an ab-initio method

TL;DR

This paper introduces a new ab initio computational method for accurately calculating magnetic exchange interactions between atoms with multiple open-shell electrons, applicable to various magnetic coupling scenarios.

Contribution

The paper presents a novel ab initio approach that improves the accuracy of magnetic coupling calculations for complex open-shell systems, covering both ferromagnetic and antiferromagnetic interactions.

Findings

High accuracy in test cases with transition metal oxides

Comparable to the best existing ab initio calculations

Consistent with experimental evaluations

Abstract

We propose a new ab initio method designed for the accurate calculation of effective exchange integrals between atoms with numerous open-shells. This method applies to ferromagnetic as well as antiferromagnetic exchange, direct or ligand-mediated exchange. Test calculations on high spin transition metal oxides such as KNiF3, Ba2CoS3 or YMnO3 exhibit a very good accuracy compared either to the best ab initio calculations --when those are feasible-- and with experimental evaluations.