Hybridization and Covalency in the Group 2 and Group 12 Metal Cation/Rare Gas Complexes.

We provide a consistent set of interaction energy curves for the group 2 (IIA) and group 12 (IIB) metal cation/rare gas complexes, M-RG, where M = Be-Ra and Zn-Hg and RG = He-Rn. We report spectroscopic constants derived from these, compare them with available data, and discuss trends in the values. We gain insight into the interactions that occur using a range of approaches: reduced potential energy curves; charge and population analyses; molecular orbital diagrams and contour plots; and Birge-Sponer plots.