X-ray absorption branching ratio in actinides: LDA plus DMFT approach

To investigate the X-ray absorption (XAS) branching ratio from the core 4d to valence 5f states, we set up a theoretical framework by using a combination of density functional theory in the Local Density Approximation and Dynamical Mean-Field Theory (LDA + DMFT), and apply it to several actinides. The results of the LDA + DMFT reduces to the band limit for itinerant systems and to the atomic limit for localized f electrons, meaning a spectrum of 5f itinerancy can be investigated. Our results provides a consistent and unified view of the XAS branching ratio for all elemental actinides, and is in good overall agreement with experiments. Copyright (C) EPLA, 2009