Mode specificity in the H + H2O → H2 + OH reaction: A full-dimensional quantum dynamics study

The initial state-selected time-dependent wave packet approach to an atom-triatom reaction is employed to study the H + H2O -> H-2 + OH reaction without the centrifugal sudden approximation. The total reaction probabilities and integral cross sections, which are the exact coupled-channel results, are calculated for the H2O reactant initially in the ground and several vibrationally excited states, including bending excited states, first and second stretching excited states, and simultaneous excitations of both bending and stretching modes. The reactivity enhancements from different initial states of the H2O reagent are presented and discussed in detail. The thermal rate constant for the title reaction and the contributions to this coefficient from individual vibrational states of H2O are also obtained and compared with the previous theoretical and experimental data. (C) 2013 AIP Publishing LLC.