FRANCK-CONDON FACTORS FOR PHOTODETACHMENT FROM LIO-, NAO-, AND KO-

The 1SIGMA+, 3SIGMA+, 1PI, and 3PI states of the negative ions and the 2PI and 2SIGMA+ states of the neutral alkali oxides are studied at high levels of theory. The calculations show that ground state of the negative ions changes from 3PI for LiO- to 1SIGMA+ for KO-. Although the calculations give a 3PI ground state for NaO-, we cannot rule out the possibility that the very low-lying 1SIGMA+ state is the true ground state. The Franck-Condon factors for photodetachment of an electron from the 1SIGMA+ and/or 3PI states of the negative ion are presented to help interpret photodetachment experiments. Our best results for the A 2SIGMA+-X 2PI separations in LiO and NaO are 2496 and 2061 cm-1, which are in excellent agreement with that deduced (2516 and 2018 cm-1) from experiment.