Theoretical study of the electronic states and transition dipole moments of the LiK+ molecule

The adiabatic potential energy, the spectroscopic constants and the transition dipole moments of the lowest electronic states of the LiK+ molecule, dissociating into Li(2s, 2p, 3s, 3p, 3d, 4s, and 4p) + K+ and Li+ + K(4s, 4p, 5s, 3d, 5p, 4d, and 6s), have been investigated. We have used an ab initio approach involving a non-empirical pseudopotential for the Li (1s2) and K (1s22s22p63s23p6) cores and core valence correlation correction. A very good agreement has been obtained for the ground state for the spectroscopic constants with the available theoretical works. The transition dipole moment from X2Σ, 22Σ, 32Σ, and 42Σ states to higher excited states have been determined. Numerous avoided crossing between electronic states of 2Σ and 2Π symmetries, have been localised and analysed. Their existences are related to the charge transfer process between the two ionic systems Li+K and LiK+.