In order to reveal correlation effect on the electronic properties in particular 5f occupation of Pu/U ions in a (Pu,U) mixed oxide-PuUO4, a first principles calculation is performed by using...

In order to investigate the structure-dependent correlation strength and occupation number of 4f electrons in cerium monoarsenide (CeAs) with the NaCl-type (B1-type) and CsCl-type (B2-type) structures, respectively, we perform a first principles calculation based on a many-body method merging density functional theory with dynamical mean-field theory (DMFT). Calculation results suggest that with the increase of the lattice constants, the Ce 4f j = 7/2 manifold maintains the insulating behavior, while the j = 5/2 component undergoes the insulating → metallic → insulating and the insulating → metallic transitions, respectively, for B1-type and B2-type structures. Quasi-particle weights demonstrate that the j = 7/2 manifold is in the weakly correlated regime, and the j = 5/2 component transforms from the weakly to moderately correlated state, irrespective of the crystal structure. Ce 4f electrons transform from a slight itinerant state into a localized state for the B1-type structure. A structure-dependent phase diagram of the occupation number suggests that the occupation numbers of individual 4f n (n = 0, 1, 2, 3) configurations and Ce 4f electrons (n f) could be modulated in terms of the crystal structure and/or the lattice constant.

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