A DETAILED SACM STUDY OF THE H-]HNO REACTION-BASED ON A REALISTIC POTENTIAL-ENERGY SURFACE(NO)

The full version of the statistical adiabatic channel model has been u sed for a detailed study of the title reaction at the limit of high pr essure for the 100-1000 K temperature range. The calculations have bee n carried out on an analytic potential energy surface for the ground s tate of HNO developed from recent high-level ab initio data. The effec ts of quantum mechanical tunneling through the barriers on the adiabat ic channel potentials are included in the calculations. The tunneling increases the rate of recombination by factors of 3.3, 1.7 and 1.08 at 100, 300 and 1000 K, respectively. The calculated rate constant at 30 0 K was found to have a difference of only 20% from the available expe rimental one. State-resolved rate constants are also presented. Calcul ations for the D+NO-->DNO reaction between 100 and 400 K were also per formed. The kinetic isotopic effect is calculated to decrease from 2.5 to 1.8 over this temperature range.