Correlation-Induced Octahedral Rotations in SrMoO$_3$

TL;DR

This study uses advanced computational methods to analyze how electronic correlations influence structural distortions in SrMoO$_3$, revealing the importance of accurate electronic modeling for predicting material properties.

Contribution

The paper demonstrates that DFT+DMFT provides a more accurate description of structural distortions in SrMoO$_3$ than DFT+$U$, emphasizing the role of electronic correlations.

Findings

DFT+DMFT predicts different ground state structure than DFT+$U$.

Structural distortions are highly sensitive to electronic correlation effects.

DFT+DMFT is robust for calculating structural properties across materials.

Abstract

Distortions of the oxygen octahedra influence the fundamental electronic structure of perovskite oxides, such as their bandwidth and exchange interactions. Utilizing a fully ab-initio methodology based on density functional theory plus dynamical mean field theory (DFT+DMFT), we study the crystal and magnetic structure of SrMoO$_3$. Comparing our results with DFT+$U$ performed on the same footing, we find that DFT+$U$ overestimates the propensity for magnetic ordering, as well as the octahedral rotations, leading to a different ground state structure. This demonstrates that structural distortions can be highly sensitive to electronic correlation effects, and to the considered magnetic state, even in a moderately correlated metal such as SrMoO$_3$. Moreover, by comparing different downfolding schemes, we demonstrate the robustness of the DFT+DMFT method for obtaining structural properties, highlighting its versatility for applications to a broad range of materials.