10min:

SPIRIDOULA MATSIKA, RUSSELL M. PITZER, Department of Chemistry, The Ohio State University, 100 W.18th Avenue, Columbus, OH 43210 .

The electronic spectrum of the neptunyl ion, NpO₂²⁺, has been calculated using relativistic spin-orbit configuration-interaction calculations. Neptunium in NpO₂²⁺ is in oxidation state VI and has an f¹ configuration. In the lower energies lie the f-> f transitions while at energies above 20000 cm^-1 charge transfer transitions occur. The ground state is a ² state with \Omega = 3/2. Equilibrium distances and vibrational frequencies for the symmetric stretch in the ground state are obtained and compared with experimental work.