* SCOTT R. BROZELL* AND RUSSELL M. PITZER, Department of Chemistry, The Ohio State University, Columbus, OH 43210.

Restricted Hartree-Fock (RHF) and spin-orbit configuration-interaction (SOCI) calculations were performed on the ground and low-lying excited states

of the americyl ion, AmO_{2}^{2+}. The RHF _{u}^{2} \, _{u}^{1} \, , ^{4}_{u} ground state symmetric stretch potential energy curve yields a frequency of 900 cm^{-1} compared to an experimental value of 730 cm^{-1} from Raman spectroscopy on aqueous solutions\footnote G.~M.~Begun *et al.* , *Inorg. Chem.* \textbf23, 1914\>(1984). of AmO_{2}^{1+}. The SOCI ground state is _{u}^{2} \, _{u}^{1} \, , ^{4}_{3/2u}; the excited states are regular components from the above term followed by irregular components from the _{u}^{1} \, _{u}^{2} \, , ^{4}_{u} term. The low energy transitions are f-> f. Analogous calculations are planned for the curyl ion, CmO_{2}^{2+}. The actinides are modeled with relativistic effective core potentials and Gaussian correlation consistent double-zeta plus polarization (cc-pVDZ) basis sets.