CLASSICAL DYNAMICS CALCULATIONS FOR THE F+H2-]HF+H REACTION ON 2 RECENT POTENTIAL-ENERGY SURFACES

State-resolved integral and differential cross sections have been calculated for the F+H-2(v=0)-->HF+H reaction by using the method of quasiclassical trajectories (QCT). The trajectories were run on the two latest versions (5SEC and 6SEC) of a partly ab initio potential energy surface. Dynamical calculations using the 6SEC surface yield branching ratios for the production of the various HF vibrational states in better agreement with experiment than those using the 5SEC one. Although the classical differential cross sections on the 6SEC surface are similar in shape to the ones obtained from accurate quantum mechanical (QM) calculations, significant differences are observed in the absolute values for the reaction with H-2(j=0), as well as in the magnitude of the forward peak, especially at the highest collision energy studied. As the initial rotational quantum number increases to j=1 and 2 at a fixed total energy the agreement between QM and QCT results improves.