AB-INITIO STUDY OF THE LIH-SPECTRUM (VOL 191, PG 119, 1995)( MOLECULE, ELECTRONIC INTERACTION ANALYSIS AND LIH UV PHOTOELECTRON)

All adiabatic curves of LiH+ dissociating into Li(2s, 2p, 3s, 3p, 3d) + H+ and Li+ + H(1s, 2s, 2p) are determined by an ab initio approach i nvolving a non-empirical pseudopotential for the Li(1s(2)) core and co re valence correlation corrections. The resulting spectroscopic consta nts and vibrational level spacings of all these states are presented. From the usual semiclassical approximations an analysis of the high en ergy vibrational level spacing is performed allowing for accurate long range extrapolations. For the lowest curves dissociating into Li+ + H (1s) and Li(2s) + H+ an analysis of the main electronic interactions i s carried out from a diabatic model and reveals the importance of the binding charge delocalisation effects versus the polarisation (charge localised) ones. In addition the LiH photoelectron spectrum is calcula ted. An interesting feature of that spectrum is that both bound-bound and bound-free transitions coexist due to the particular shape of the LiH and LiH+ potential energy curves.