Theoretical study of Ban+–RG (RG=rare gas) complexes and transport of Ban+ through RG (n=1,2; RG=He–Rn)

We present high-level ab initio potential energy curves for barium cations and dications interacting with RG atoms (RG=rare gas). These potentials are employed to derive spectroscopic parameters for the Ba+–RG and Ba2+–RG complexes, and also to derive the transport coefficients for Ba+ and Ba2+ moving through a bath of the rare gas. The results are compared to the limited experimental data, which generally show reasonable agreement. We identify a large change in binding energy going from Ba+–He and Ba+–Ne to Ba+–Ar, which is not present in Ba2+–RG, and show that this is due to significant dispersion interactions in Ba+–RG.