A Quantum Mechanical Study of the k-j and k'-j' Vector Correlations for the H + LiH → Li + H2 Reaction.

We have characterized the stereodynamics of the H + LiH (v = 0, j = 0-1) reactive collisions leading to H2 formation through the quantum mechanical analysis of the k-j and k'-j' vector correlations that describe the polarization of the reactants and products, respectively. Our results, which cover the collision energy interval between 10-4 and 1 eV, are unexpectedly complex given the apparent simplicity and featureless nature of the potential energy surface for the LiH2 system and point toward the existence of a dynamical barrier connected to the centrifugal barrier. Both reactants and products, in particular the second ones, display strong directional preferences in the cold region that indicate a bias for collinear approaching and departing geometries and are independent of the final state of the products. As more energy is available for the reaction, the polarization of reactants and products becomes weaker and strongly dependent on the final state. While stereodynamical control is feasible and significant in the cold region, its extent becomes negligible for other energetic regimes.