A many-body perspective on dual 5f states in two plutonium hydrides

Abstract

In order to capture the occupation numbers as well as the dual behaviors for Pu 5f electrons in two typical plutonium hydrides (PuH2 and PuH3), we perform a first principles calculation on electronic properties of these two systems using a many-body method by combination of density functional theory (DFT) with dynamical mean field theory (DMFT) including the on-site Coulomb repulsion between Pu 5f states and spin-orbit coupling (SOC) effect. Results demonstrate that both PuH2 and PuH3 have dual 5f states, i.e., the localized and itinerant regimes, with average 5f occupations of 4.968 and 4.989, respectively. Spectrum function shows that plutonium hydrides will transform from metallic (PuH2) to semi-conducting (PuH3) states with the increasing of H content, while Pu 5f j = 5/2 and j = 7/2 manifolds both exhibit the insulating behaviors. Finally, the density of states (DOS), hybridization function as well as momentum-resolved electronic spectrum function are also discussed.