First-principles study of α-Pu2O3

We systematically investigate the electronic structure, magnetic order, and valence of α-Pu2O3 (C-type) by using first-principles calculations. Our results show that more electrons are condensed into localized Pu 5f orbitals in α-Pu2O3 compared to PuO2. This phenomenon is demonstrated by the combined fact that (i) the volume per unit cell expands 7% and (ii) the corresponding magnetic moments and valence for Pu ions increase and decrease, respectively. According to the density of states and charge density distribution analysis, PuO2 is also found to be more covalent than α-Pu2O3. The calculated lattice constants and electronic structures for PuO2 and α-Pu2O3 are consistent well with experimental observations.