A density functional theory study of FeAs comparing LDA+U, GGA+U and hybrid functionals

TL;DR

This study employs various density functional theory methods to analyze the structural, magnetic, and electronic properties of FeAs, comparing their effectiveness and accuracy against experimental data and exploring the origin of magnetic spirals.

Contribution

It systematically compares LDA+U, GGA+U, and hybrid functionals for FeAs, providing insights into their suitability for describing Fe-pnictide superconductors.

Findings

GGA+U best matches experimental magnetic properties

Hybrid functionals accurately predict electronic structure

LDA+U provides reliable structural parameters

Abstract

We use density functional theory within the local density approximation (LDA), LDA+U, generalized gradient approximation (GGA), GGA+U, and hybrid-functional methods to calculate the properties of iron monoarsenide. FeAs, which forms in the MnP structure, is of current interest for potential spintronic applications as well as being the parent compound for the newly-identified pnictide superconductors. We compare the calculated structural, magnetic and electronic properties obtained using the different functionals to each other and to experiment, and investigate the origin of a recently-reported magnetic spiral. Our results indicate the appropriateness or otherwise of the various functionals for describing FeAs and the related Fe-pnictide superconductors.