Nonadiabatic quantum reactive scattering calculations for the O(1D)+H2, D2, and HD reactions on the lowest three potential energy surfaces

Time-independent three-dimensional quantum reactive scattering calculations including the effect of electronically nonadiabatic coupling have been carried out for the O(D-1)+H-2, D-2, and HD reactions using the recent ab initio versions of the lowest three potential energy surfaces (1 (1)A('), 2 (1)A('), and 1 (1)A()) of Dobbyn and Knowles. The hyperspherical close-coupling technique has been used and the calculations have been carried out only for zero total angular momentum (J=0). We present total reaction probabilities, the effect of initial rotational excitation, and cumulative reaction probabilities. We found that electronically nonadiabatic transitions are very important for these reactions similar to previous nonadiabatic wave packet calculations using the same surfaces but found isotopic substitution does not largely affect the nonadiabatic reaction dynamics. We also calculated the OH/OD isotopic branching fraction for the O(D-1)+HD reaction and found that the OD+H production channel is dominant over the OH+D channel in the energy range considered. (C) 2002 American Institute of Physics.