ON THE COUPLING OF ROTOVIBRATIONAL MOTIONS IN HE-LI2 INELASTIC-COLLISIONS

He-Li2 interaction potentials, which explicitly include both angular anisotropy and internal vibrational coordinates, have been proposed recently in the literature by extracting them from laser-selected, crossed beam experiments and from the use of various perturbation expansions. In view of the importance of assessing as accurately as possible the dynamical coupling of such internal degrees of freedom during inelastic, low-energy collisions, the present study undertakes a detailed computational comparison of the various possible decoupling schemes which can be employed to treat the above processes. It is found that because of the rather weak nature of the interaction in the title system, nearly all schemes work reasonably well and can be used in scattering calculations. It is, however, shown that the previously suggested potentials need to be modified extensively in order to yield cross sections which agree with the experimental findings.