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

The local-density approximation combined with the dynamical mean-field theory (LDA+DMFT) is applied to the paramagnetic phase of light actinide dioxides: UO₂,0.16em0exNpO₂, and PuO₂. The calculated band gaps and the valence-band electronic structure are in 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.