A detailed SACM study of the H+NO→HNO reaction based on a realistic potential energy surface

Abstract

The full version of the statistical adiabatic channel model has been used for a detailed study of the title reaction at the limit of high pressure for the 100–1000 K temperature range. The calculations have been carried out on an analytic potential energy surface for the ground state of HNO developed from recent high-level ab initio data. The effects of quantum mechanical tunneling through the barriers on the adiabatic 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 300 K was found to have a difference of only 20% from the available experimental one. State-resolved rate constants are also presented. Calculations for the D+NO→DNO reaction between 100 and 400 K were also performed. The kinetic isotopic effect is calculated to decrease from 2.5 to 1.8 over this temperature range.