QUASI-CLASSICAL TRAJECTORY CALCULATIONS OF THE THERMAL RATE COEFFICIENTS FOR THE REACTIONS H(D)-]OH(D)+O AND O+OH(D)-]O2+H(D) AS A FUNCTIONOF TEMPERATURE(O2)

Thermal rate coefficients are calculated for the reaction, (1), H + O2 --> OH + O and its reverse, (-1), O + OH --> O2 + H, using the quasic lassical trajectory method and the most recently reported double many- body expansion (DMBE IV) potential energy surface for the ground elect ronic state of the hydroperoxyl radical. The full range of temperature s for which experimental data is available in the literature has been covered, namely, 1000 less-than-or-equal-to T less-than-or-equal-to 30 00 K for reaction (1) and 150 less-than-or-equal-to T less-than-or-equ al-to 3000 K for reaction (-1). The equilibrium constant has also been evaluated. In addition, calculations of the isotopic effect on the th ermal rate coefficient for the deuterated reactions D + O2 --> OD + O and O + OD --> O2 + D, and equilibrium constant, are reported. The the oretical results are shown to be in good agreement with the most recen t and accurate experimental measurements.