The relativistic 5f electronic structure of delocalized $\alpha$-U and localized $\delta$-Pu from the self consistent vertex corrected GW approach and X-ray Emission Spectroscopy.

The recently developed self-consistent vertex corrected GW method is used to calculate the 5f electronic structure in delocalized $\alpha$-U and localized $\delta$-Pu, each of which is confirmed by the historical experimental approaches of direct and inverse photoemission. Tender X-Ray Emission Spectroscopy (XES), in a novel application to 5f electronic structure, is used to experimentally prove the existence of 5f delocalization in $\alpha$-U.