Electronic structure and core-level spectra of light actinide dioxides in the dynamical mean-field theory

TL;DR

This paper applies LDA+DMFT to light actinide dioxides, accurately modeling their electronic structure, band gaps, and core-level spectra, revealing significant hybridization effects and satellite features.

Contribution

The study demonstrates the effectiveness of LDA+DMFT in reproducing experimental electronic and core-level spectra of UO2, NpO2, and PuO2, highlighting hybridization effects.

Findings

Calculated band gaps agree with optical and photoemission data

Hybridization increases 5f orbital filling to nearly half-integer values

Core-level satellite peaks are accurately reproduced by the model

Abstract

The local-density approximation combined with the dynamical mean-field theory (LDA+DMFT) is applied to the paramagnetic phase of light actinide dioxides: UO2, NpO2, and PuO2. The calculated band gaps and the valence-band electronic structure are in a very good agreement with the optical absorption experiments as well as with the photoemission spectra. The hybridization of the actinide 5f shell with the 2p states of oxygen is found to be relatively large, it increases the filling of the 5f orbitals from the nominal ionic configurations with two, three, and four electrons to nearly half-integer values 2.5, 3.4 and 4.4. The large hybridization leaves an imprint also on the core-level photoemission spectra in the form of satellite peaks. It is demonstrated that these satellites are accurately reproduced by the LDA+DMFT calculations.