Heavy-element effect on the splitting of the A 2Π state of the LiRg (Rg=Ar, Kr and Xe) complexes

The spin–orbit splittings ASO (R) of the A 2Π state of LiRg (Rg=Ar, Kr and Xe) complexes have been obtained from the configuration interaction calculations using relativistic effective core potentials and two-component spinors. The results confirm that the mixing between the p orbitals of the lithium atom and the valence np orbitals (and not the Rydberg orbitals) of the rare gas (Rg) atom produces a large ASO (R) for the A 2Π states at short internuclear distances. The spectroscopic constants for the ground and A states of LiRg complexes are also reported.