Spectroscopic properties of the molecular ions BeX⁺ (X=Na, K, Rb): forming cold molecular ions from an ion–atom mixture by stimulated Raman adiabatic process

In this theoretical work, we calculate potential energy curves, spectroscopic parameters and transition dipole moments of molecular ions BeX⁺ (X=Na, K, Rb) composed of alkaline ion Be and alkali atom X with a quantum chemistry approach based on the pseudopotential model, Gaussian basis sets, effective core polarisation potentials and full configuration interaction. We study in detail collisions of the alkaline ion and alkali atom in quantum regime. Besides, we study the possibility of the formation of molecular ions from the ion–atom colliding systems by stimulated Raman adiabatic process and discuss the parameters regime under which the population transfer is feasible. Our results are important for ion–atom cold collisions and experimental realisation of cold molecular ion formation.