Electronic structure with dipole moment calculations of the high-lying electronic states of BeH, MgH and SrH molecules

By using the complete active space self consistent field (CASSCF) with multi-reference configuration interaction MRCI+Q method including single and double excitations with Davidson correction, the 26, 27 and 25 low-lying doublet and quartet electronic states in the representation^2s+1Λ^(+/−) (without spin orbit interaction) of the molecules BeH, MgH and SrH have been investigated. The potential energy curves, the internuclear distance R_e, the harmonic frequency ω_e, the permanent dipole moment μ, the rotational constant B_e and the electronic transition energy with respect to the ground state T_e are calculated. Using the canonical approach the eigenvalue E_v, the rotational constant B_v and the abscissas of the turning points R_min and R_max have been calculated for the investigated electronic states. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement.