Double-well of the C2ϵ+ state of LiAr

The X2ϵ+, A2Π, B2ϵ+ states of LiAr and the ground state of LiAr+ are calculated by configuration interaction methods. The existence of a double potential well is found for the C2ϵ+ state. The origin of the double well is surmised to lie in the existence of a nodal plane separating two radial regions of the electron density in the Rydberg atomic orbital. The spectroscopic constants and the transition properties between the calculated states are also reported.