Orbital-slective behaviour in cubanite CuFe2S3

TL;DR

This study uses ab initio calculations to reveal that cubanite CuFe₂S₃ exhibits orbital-selective behavior, with some electrons in molecular orbitals and others localized, explaining several experimental observations.

Contribution

It is the first to demonstrate orbital-selective behavior in cubanite using ab initio band structure calculations, linking electronic structure to experimental phenomena.

Findings

Orbital-selective behavior observed in CuFe₂S₃

Explains absence of charge disproportionation

Accounts for ferromagnetic ordering and M"ossbauer data

Abstract

Using {\it ab initio} band structure calculations we show that mineral cubanite, CuFe$_2$S$_3$, demonstrates an orbital-selective behavior with some of the electrons occupying molecular orbitals of $x^2-y^2$ symmetry and others localized at atomic orbitals. This is a rare situation for $3d$ transition metal compounds explains experimentally observed absence of charge disproportionation, anomalous M\"ossbauer data, and ferromagnetic ordering in between nearest neighbor Fe ions.