Knowledge Bank

Potential energy curves for the ground $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g\ast$ state of $Xe2$, the first four states of the positive $Xe2+$ ion, and the eight $Xe2\ast$ excimer states corresponding to the addition a $6\Sigma g$ Rydberg electron to these ion cores have been computed using averaged relativistic effective core potentials (AREP) and the self-consistent field approximation for the valence electrons. The calculations were carried out using the LS-coupling scheme with the effects of spin-orbit coupling included in the resulting potential energy curves using an empirical procedure. A comparison of non-relativistic and averaged relativistic EP’s and subsequent molecular calculations indicates that relativistic effects arising from the mass-velocity and Darwin terms are not important for these properties of $Xe2$ molecules. Spectroscopic constants for $Xe2+$ are in good agreement with all electron CI calculations suggesting that the computed values for $Xe2\ast$ excimers should be reliable. The lifetimes for the lower states of $Xe2\ast$ are computed.