Electronic states and spectroscopic properties of MgH in absence and presence of spin-orbit coupling - a configuration interaction study

Electronic spectrum of astrophysically important molecule magnesium hydride (MgH) has been studied using configuration interaction methodology excluding and including spin-orbit coupling. Potential energy curves of several spin-independent (Lambda- S) electronic states have been constructed and spectroscopic constants of low-lying bound Lambda - S states within 8.2 eV of term energy are reported in the first stage of calculations. The X-2 Sigma(+) is identified as the ground state in the Lambda-S level. In the subsequent stage, the spin-orbit interaction has been incorporated and its effects on the potential energy curves and spectroscopic features of different electronic states of the species have been inves2 tigated. The X-2 Sigma(+)(1/2) is identified as the spin-orbit(Omega) ground state of the species. Transition moments of several dipole-allowed transitions are computed in both the stages and radiative lifetimes of the corresponding excited states are computed. Electric dipole moments (mu) for a number of low-lying bound A-S states as well as several low-lying Omega-states, are also calculated in the present study.