Radiative Lifetimes of LiK[sup +], LiRb[sup +] and LiCs[sup +] in the 2[sup 2]Σ[sup +] State

Abstract

The adiabatic potential energy curves and the spectroscopic constants of the ground and the first excited states of LiK+, LiRb+ and LiCs+ ionic molecules have been performed. The transition dipole moment between the ground (X2Σ+) and the first excited (22Σ+) state have been determined for each ionic molecule. We have used an ab initio approach involving non‐empirical pseudo‐potentials with core valence effects taken into account through parameterized l‐dependent polarization potentials. Our spectroscopic constants of the ground and the first excited states are in good agreement with the available theoretical works. The potential energy curves and the transition dipole moment are used to estimate the radiative lifetimes of the vibrational levels of the 22Σ+ state for the first time. In addition to the bound‐bound contribution, the bound‐free term has been evaluated exactly and using the Franck‐Condon (FC) approximation and added to the total radiative lifetime. These data can help experimentalists to optim...