Thermal and state‐selected rate constant calculations for O(3p) + H2 → OH + H and isotopic analogs

Abstract We present a new parametrization (based on ab initio calculations) of the bending potentials for the two lowest potential energy surfaces of the reaction O( 3 P ) + H 2 , and we use it for rate constant calculations by variational transition‐state theory with multidimensional semiclassical tunneling corrections. We present results for the temperature range 250–2400 K for both the rate constants and the intermolecular kinetic isotope effects for the reactions of O( 3 P ) with D 2 and HD. In general, the calculated rate constants for the thermal reactions are in excellent agreement with available experiments. We also calculate the enhancement effect for exciting H 2 to the first excited vibrational state. The calculations also provide information on which aspects of the potential energy surfaces are important for determining the predicted rate constants.