Ab-initio calculations of the electronic structure of the alkaline earth hydride anions XH- (X = Mg, Ca, Sr and Ba) toward laser cooling experiment.

Abstract

By the use of the ab initio CASSCF/(MRCI+Q) calculations in the representation 2s+1Λ(+/-), the adiabatic potential energy curves and the dipole moment curves of the low lying states of the alkaline earth hydride anions (MgH-, CaH-, SrH- and BaH-) have been investigated in their singlet and triplet multiplicities. The spectroscopic parameters Te, Re, ωe, Be, αe, the dipole moment μe, and the dissociation energy De have been also calculated for the bound states of the considered molecules. In addition, a systematic investigation of the transition dipole moment curves for the lowest 1Σ+-1Π transitions has been done along with the Franck-Condon factor (FCF) corresponding to the X1Σ+-(1)1Π transition. Using the canonical function approach, a rovibrational study has been performed for finding the rovibrational constants Ev, Bv, Dv and the turning points Rmin and Rmax for the ground and different excited bound state. Efficient routes may be achieved via the diagonal FCF for the formation of cold and ultracold alkaline earth hydride anions. PACS N: 31.10. + z, 31.15.A, 31.15.vn, 31.50.Df.