Importance of electronic correlations for structural and magnetic properties of the iron pnictide superconductor LaFeAsO

TL;DR

This study demonstrates that including electronic correlations via a combined DFT and DMFT approach significantly improves the theoretical prediction of structural and magnetic properties of LaFeAsO, aligning well with experimental observations.

Contribution

The paper introduces a fully charge self-consistent DFT+DMFT method to accurately predict structural and magnetic properties of LaFeAsO, highlighting the importance of electron correlations.

Findings

Correlation effects improve arsenic z position predictions.

Ordered magnetic moment matches experimental value.

Enhanced agreement with experimental structural and magnetic data.

Abstract

We present calculations of structural and magnetic properties of the iron-pnictide superconductor LaFeAsO including electron-electron correlations. For this purpose we apply a fully charge self-consistent combination of Density-Functional Theory with the Dynamical Mean-Field theory, allowing for the calculation of total energies. We find that the inclusion of correlation effects gives a good agreement of the Arsenic z position with experimental data even in the paramagnetic (high-temperature) phase. Going to low temperatures, we study the formation of the ordered moment in the striped spin-density-wave phase, yielding an ordered moment of about 0.60, again in good agreement with experiments. This shows that the inclusion of correlation effects improves both structural and magnetic properties of LaFeAsO at the same time.