Self-consistent field calculation of the electronic structure of the uranyl ion (UO2++)

Abstract
Using the multiple‐scattering Xα method the electronic ground state (1Σ+g) of the UO++2 molecule has been calculated self‐consistently. The self‐consistent calculations were performed at three U–O bond distances [3.269, 4.269, and 5.269 (a.u.)]. The four highest occupied one‐electron levels (σg, σu, Πg, Πu) of the ground state, which have received so much attention in the past, change ordering with decreasing bond distance but are so close in energy that the ordering may be unimportant in determining the absorption spectra. We have also computed the electronic transition energies for the excitations 1Σ+g1,3Φg1uφ1u), 1Σ+g1,3Δg1uφ1u), 1Σ+g1,3Πu, 1,3Φu3gδ1u), 1Σ+g1,3Δg, 1,3Γg3uφ1u), and 1Σ+g1,3Φg, 1,3Πg3uφ1u). All of these excitation energies fall in the region of the experimental absorption spectrum.