AB INITIO CALCULATION OF $UO_{2}$

Abstract

Ab initio spin-orbit configuration interaction calculations are performed on the $UO_{2}$ molecule, which has been observed in matrix isolation and vacuum ultraviolet spectroscopic studies. $UO_{2}$ is isoelectronic with $PuO_{2}^{2+}$, which has a $5f\delta^{1}5f\varphi^{1} {^{3}H}{4g}$ ground state. We find, as have other workers, that $UO{2}$ has a $5f\varphi^{1}7s\sigma^{1} {^{3}\Phi}{2}$ ground state with a moderate mixture of $5f\delta^{1}7s\sigma^{1} {^{3}\Delta{2}}$. the UO distance is found to be $1.786 \dot{A}$. The $^{3}H_{4g}$ state is only slightly higher in energy. Oscillator strengths have been calculated for electronic transitions.