To demonstrate that the population analysis indeed corresponds directly to the extent of orbital (de)localization, Figure shows the NLMOs representing the LM σdonation in PuO 2 . With increasing fraction of eX (left to right in Figure ), the σ(O-Pu) bond NLMOs become increasingly polarized toward the oxygens. Therefore, as posited already, the extent of orbital delocalization is directly associated with the extent of LM donation in the system. Note that on the metal side the NLMOs have dominant 5f-6d hybrid character with varying local compositions reflecting the dependence of the donation into the 5f-shell on the chosen functional.