The low-lying electronic states of the MgAl molecule

The low-lying electronic states of MgAl are investigated at a high level of electron correlation treatment using the CASSCF/MRCI approach, and the aug-cc-pVQZ basis set. Besides the confirmation of the ground state (X 2Π) and the first excited state ((1) 2Σ+), this study also provides a very accurate spectroscopic characterization of the lowest-lying doublet and quartet states. The behavior of the dipole moment and the transition dipole moment functions with internuclear distance are also described. Relative intensities for the (2) 2Π → X 2Π, (3) 2Π → X 2Π and (1) 2Δ → X 2Π band systems are predicted by the Einstein coefficients.