Structural investigation for the low-lying electronic states with rovibrational calculations of the alkaline-earth fluoride cations XF+ (X = Be, Mg, Ca)

Abstract

Due to the lack of theoretical data about the electronic structure on the molecular cations BeF+, MgF+ and CaF+, an accurate ab initio calculations have been investigated for these molecules using the multi-reference configuration interaction plus Davidson correction (MRCI + Q) method. The potential energy curves (PECs) of the low-lying electronic states in the representation 2s+1Ʌ(+/-) of the three alkaline-earth fluoride cations have been computed. The spectroscopic constants Te, Re, ωe, Be, αe, the dipole moment µe, and the dissociation energy De have been calculated for the bound states. Moreover, the transition dipole moment curves (TDMCs) of the (X)1Σ+-(1)1Π, (X)1Σ+-(2)1Σ+ and (1)1Π-(2)1Σ+ transitions have been analyzed. A rovibrational study has been done to investigate the vibrational levels of the bound states and the vibrational constants Ev, Bv, Dv, Rmin and Rmax are calculated. These theoretical results are quite interesting for further experimental works, especially, in the advancement of creation of cold alkaline-earth monofluoride cations in the low-lying vibrational states.