Spatial energetics of protonated LiH: lower-lying potential energy surfaces from valence bond calculations

The detailed features of the interaction forces within the LiH2+ triatomic system are calculated using the spin-coupled valence bond (SCVB method in terms of the three Jacobi coordinates of the LiH(LiH+) and H+/H fragments within a broad range of relative orientations and of internuclear distances. The specific features of the systems and of their asymptotic molecular fragments are examined with the view of estimating from them the collisional probabilities for producing rovibrationally excited partners with detectable radiative behavior. The possibility of having a charge transfer process within the two electronic states of the LiH2+ ion is also analyzed and discussed. The calculations suggest, albeit still qualitatively, that a direct charge-transfer reaction between LiH + H+ into LiH+ + H is unlikely to take place during bimolecular collisions in a low-density medium.