Many-body Electronic Structure of Metallic alpha-Uranium

TL;DR

This paper applies a novel quasiparticle self-consistent GW method to alpha uranium, revealing significant f-electron shifts and narrowing, and explaining why simpler methods like LDA still effectively predict its ground-state properties.

Contribution

First first-principles treatment of f-electron interactions in an actinide using QSGW, advancing understanding of uranium's electronic structure.

Findings

f-level shifted upwards by ~0.5 eV

significant f-band narrowing compared to LDA

ground-state properties unaffected by f-electron correlation effects

Abstract

We present results for the electronic structure of alpha uranium using a recently developed quasiparticle self-consistent GW method (QSGW). This is the first time that the f-orbital electron-electron interactions in an actinide has been treated by a first-principles method beyond the level of the generalized gradient approximation (GGA) to the local density approximation (LDA). We show that the QSGW approximation predicts an f-level shift upwards of about 0.5 eV with respect to the other metallic s-d states and that there is a significant f-band narrowing when compared to LDA band-structure results. Nonetheless, because of the overall low f-electron occupation number in uranium, ground-state properties and the occupied band structure around the Fermi energy is not significantly affected. The correlations predominate in the unoccupied part of the f states. This provides the first formal justification for the success of LDA and GGA calculations in describing the ground-state properties of this material.