The O(1D)+H2 reaction at 56 meV collision energy:: A comparison between quantum mechanical, quasiclassical trajectory, and crossed beam results

Quantum mechanical and quasiclassical trajectory reactive scattering calculations have been performed for the O(D-1)+H-2 (v=0,j=0) reaction on the Dobbyn-Knowles ab initio 1 (1)A(') and 1 (1)A(') potential energy surfaces (PES) at the mean collision energy E-col=56 meV (1.3 kcal/mol) of a crossed beam experimental study based on H-atom Rydberg tagging time-of-flight detection. Novel data from this latter experiment are presented and compared with the theoretical results at the level of state-resolved integral and differential cross sections and product recoil energy distributions. A good overall agreement with small discrepancies is found between the experimental data and the results of the two theoretical approaches. The main conclusion of the present work is that the contribution of the ground state 1 (1)A(') PES to the global reactivity accounts for the experimental observations and that, at the title collision energy, the participation of the 1 (1)A(') PES in the reaction is negligible for all practical purposes. (C) 2002 American Institute of Physics.