AB INITIO STUDY OF THE AMERICYL AND CURYL IONS

Abstract

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 $\delta_{u}^{2}\phi_{u}^{1},^{4}\Phi_{u}$ 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 $solutions^{a}$ of $AmO^{1+}_{2}$. The SOCI ground state is $\delta_{a}^{2}\phi_{u}^{1},{^{4}}\Phi_{3/2u}$; the excited states are regular components from the above term followed by irregular components from the $\delta_{u}^{1}\phi_{u}^{2}m{^{1}}\Delta_{u}$ term. The low energy transitions are $f \to f$. 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-p VDZ) basis sets.