Electronic structure and geometry optimization of hexavalent plutonyl nitrate by the relativistic density functional calculation

Metal-ligand distances of Pu = O (plutonyl oxygen) and Pu-OH₂ in the plutonyl nitrate dihydrate have been optimized using the all-electron fully relativistic density functional theory (RDFT) method. The calculated bond dtetances of Pu = O and Pu-OH₂ were in good agreement with the experimental results. The shape of the potential curve indicates that the strength of the Pu = O bond is stronger than that of the Pu-OH₂ bond. The Pu = O bond is mainly constructed by strong covalent interaction between Pu 6d, 5f orbitals and O 2p orbital, however the covalent interaction is not so significant in the Pu-OH₂ bond.