Valence and excited states of LiH-

Valence and excited dipole-bound states of the LiH- anion are calculated with the recently developed electron-attachment equation-of-motion coupled-cluster technique. It is found that the first dipole-bound state of LiH- corresponds to the second dissociation channel LiH- --> Li-(S-1) + H(S-2). The second (excited) dipole-bound state of LiH- is below the neutral ground-state potential energy curve only for some range of the LI-H internuclear distance. This state appears at bond lengths larger than approximate to 2.0 Angstrom and decays at Li-H distances longer than approximate to 4.2 Angstrom, where the dipole moment of LiH becomes smaller than the critical value of 2.5 D. The adiabatic electron affinity of LiH calculated at the coupled-cluster level with the iterative inclusion of all single, double, and triple excitations and a large atomic natural orbital basis set is 0.327 eV, almost matching the recently obtained experimental value of 0.342 +/- 0.012 eV.