Numerical multiconfiguration self-consistent-field calculations on the first excited state of LiH^-

We have carried out numerical multiconfiguration self-consistent-field (MCSCF) calculations on the first excited state of LiH^- in order to investigate the importance of electron correlation in excited states of anions of highly polar molecules. A discussion of the configuration selection and orbital optimization procedures is given. Comparison calculations were carried out on LiH so that an estimate of the electron binding energy could be made. Our best estimate, 95 μhartrees, is compared with the pseudopotential value obtained by Garrett. Some possible general conclusions regarding electron correlation in excited-state anions of this type are presented.