Ab initio study of the feasibility of laser cooling of ScO molecule

Using ab initio quantum chemistry method, the feasibility of laser cooling ScO was investigated. The ground state X-2 sigma(+) and low-lying excited states Alpha(2)pi, Alpha '(2)Delta are calculated at the multi-reference configuration interaction (MRCI) level of theory. The calculated spectroscopic constants are in good agreement with available theoretical and experimental results. At the MRCI level of theory with Davidson correction, the permanent dipole moments of the X-2 sigma(+) and Alpha(2)pi states of ScO are also calculated. The highly diagonally distributed Franck-Condon factors and shorter radiative lifetime for the Alpha(2)pi -> X-2 sigma(+) transition are calculated with the corresponding potential energy curves and transition dipole moment. Although there is an intermediate state Alpha '(2)Delta, the loss will be dominated by branching to the intermediate electronic state Alpha '(2)Delta at a level of eta < 1.4 x 10(-4). These results demonstrate the probability of laser cooling of ScO, and we provide a promising laser-cooling scheme for ScO molecule.