Correlation-Induced Octahedral Rotations in SrMoO$_3$

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 accurately predict the crystal and magnetic structure of SrMoO3. Comparing our results with DFT+U performed on the same footing, we find that DFT+U overestimates octahedral rotations leading to a different ground state structure. This demonstrates that structural distortions can be highly sensitive to electronic correlation effects, even in a moderately correlated metal such as SrMoO3. 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.

Electronic Origin of Non-Zone-Center Phonon Condensations: Octahedral Rotations as A Case Study

“…Even though this explanation is useful for foreseeing whether a given material will exhibit ORs or not, it lacks the ability to predict the rotational pattern, which is actually sensitive to electron correlations as reported in Ref. [23]. A deep insight would be highly desirable for harnessing nonzero-q displacements and paving a promising route to manipulate the materials functionality.…”