The semiempirical MINDO/3 CI method was employed for studies of the electronical spectra of the diatomic hydrides. It was shown that this approach was very satisfactory for study of the electronical structure and for qualitative estimation of the features in the spectra. The intensity of the spin-forbidden transition in diatomic species were calculated on the basis of the MINDO/3 CI method and spin-orbit coupling (SOC) has been taken into account as a perturbation. Fine structure constant (SOC constant A for3states, spin-rotation and zero-field splitting for3σ−state) were obtained and verified by experiment where possible.