Structural relaxation due to electronic correlations in the paramagnetic insulator KCuF3

TL;DR

This paper presents a computational method combining ab initio calculations and dynamical mean-field theory to study how electronic correlations induce structural relaxation in complex materials, exemplified by KCuF3.

Contribution

It introduces a new computational scheme capable of modeling atomic displacements caused by electronic correlations in strongly interacting electron systems.

Findings

Equilibrium Jahn-Teller distortion matches experimental data.

Antiferro-orbital order consistent with observations.

Method successfully captures correlation-driven structural relaxation.

Abstract

A computational scheme for the investigation of complex materials with strongly interacting electrons is formulated which is able to treat atomic displacements, and hence structural relaxation, caused by electronic correlations. It combines ab initio band structure and dynamical mean-field theory and is implemented in terms of plane-wave pseudopotentials. The equilibrium Jahn-Teller distortion and antiferro-orbital order found for paramagnetic KCuF3 agree well with experiment.