Detailed energy dependences of cross sections and rotational distributions for the Ne+H2+→NeH++H reaction

Detailed energy dependences of state-to-state and state-to-all integral cross sections have been studied by means of exact three-dimensional hyperspherical calculations, for the complex-forming Ne + H-2(+) --> NeH+ + H reaction. Integral cross sections show an outstandingly marked structure as a function of energy. This structure has been characterized analyzing the state-to-state contributions, on one hand, and the partial cross section cumulative sums as a function of the total angular momentum quantum number J, on the other. As expected, the key fact is that strongly bound metastable states lead to peaks in the above quantities narrow enough to avoid an effective quenching of the resulting structure, when summing either over J or over final product states. This feature, which has already been found for other complex-forming reactions, indicates that quantum effects can be more relevant than expected, so as to require their explicit consideration when accurately characterizing a reactive event. Additionally, the implications of the observed behavior for the J-shifting approximation have been analyzed. In particular, it is shown how a clear J-shifting behavior is found for low J, Omega = 0. However, it is lost as higher J values are considered (for Omega = 0) or, as it is well known, higher Omega projections are included in the calculation. A rationale for this behavior is presented.