5f electron localization-delocalization transition from UPd3 to UPt3 -: art. no. 216403

The electronic structures of URh3 , UPd3 , UPt3 , and UAu3 are calculated with the self-interaction corrected local-spin-density approximation. We find that only in URh3 the f electrons are fully delocalized. UPt3 has one f electron localized at each U site, while a localized f(2) configuration of the U ion is found for UPd3 . It is predicted that, upon application of a pressure of 25 GPa, UPd3 will acquire the f(1) configuration and possibly exhibit heavy-fermion behavior. We find that UAu3 is characterized by the same mixed localized-delocalized f-electron manifold as UPd3 .