The role of correlations in the high-pressure phase of FeSe

TL;DR

This study uses first-principle calculations to explore how correlations affect the electronic structure of high-pressure FeSe, revealing its semiconducting nature across a broad pressure range.

Contribution

It provides a systematic analysis of the high-pressure phase of FeSe using hybrid functionals and Hubbard U, clarifying the role of correlations in its electronic properties.

Findings

FeSe remains semiconducting up to 30 GPa

Hybrid functionals and Hubbard U correctly predict the ground state

Pressure influences the electronic structure and correlations

Abstract

We present a systematic study of the high-pressure FeSe phase performed by means of the first-principle electronic structure calculations. Basing on available experimental information about the unit cell geometry we calculate the band structure and characterize the related properties during their pressure driven evolution. The electronic structure including the hybrid functional B3LYP or the Hubbard parameter U for the iron d states lead to the correct semiconducting ground state for the hexagonal stoichiometric FeSe within the broad pressure range (up to 30 GPa).