Electron correlation and spin-orbit coupling effects in US3 and USe3

TL;DR

This study uses DFT+U calculations to analyze electron correlation and spin-orbit coupling effects in US3 and USe3, revealing their electronic structure, magnetic properties, and the importance of correlation effects.

Contribution

It provides a systematic DFT+U analysis of US3 and USe3, highlighting the role of electron correlation and SOC in their electronic and magnetic properties.

Findings

US3 has a direct band gap; USe3 has an indirect band gap.

Both materials are antiferromagnetic insulators.

SOC slightly reduces band gaps but significantly alters band shapes.

Abstract

A systematic density functional theory (DFT)+U study is conducted to investigate the electron correlation and spin-orbit coupling (SOC) effects in US3 and USe3. Our calculations reveal that inclusion of the U term is essential to get energy band gaps for them, indicating the strong correlation effects for uranium 5f electrons. Taking consideration of the SOC effect results in small reduction on the electronic band gaps of US3 and USe3, but largely changes the energy band shapes around the Fermi energy. As a result, US3 has a direct band gap while USe3 has an indirect one. Our calculations predict that both US3 and USe3 are antiferromagnetic insulators, in agreement with corresponding experimental results. Based on our DFT+U calculations, we systematically present the ground-state electronic, mechanical, and Raman properties for US3 and USe3.