TY - JOUR

T1 - Interpolated variational transition state theory and tunneling calculations of the rate constant of the reaction OH+CH4 at 223-2400 K

AU - Melissas, Vasilios S.

AU - Truhlar, Donald G

PY - 1993/1/1

Y1 - 1993/1/1

N2 - We have carried out ab initio calculations for the reaction OH+CH 4→H2O+CH3 using second-order Møller-Plesset perturbation theory, employing a very large basis set and scaling all correlation energy for the final energy calculation, but optimizing the equilibrium and transition state structures without scaling (MP-SAC2//MP2). We found that inclusion of correlation energy has an important effect on the geometry, barrier height, and vibrational frequencies of the transition state. The final calculated values for the forward and reverse classical barrier heights are 7.4 and 20.6 kcal/mol, respectively. We have used these with interpolated canonical variational transition state theory and the centrifugal-dominant small-curvature tunneling approximation, including information at the reactants, products, transition state, and two other points along the minimum energy path, to predict the rate constants for the above reaction in the temperature range from 223 to 2400 K. The calculated rate constants agree well with experiment over a wide temperature range.

AB - We have carried out ab initio calculations for the reaction OH+CH 4→H2O+CH3 using second-order Møller-Plesset perturbation theory, employing a very large basis set and scaling all correlation energy for the final energy calculation, but optimizing the equilibrium and transition state structures without scaling (MP-SAC2//MP2). We found that inclusion of correlation energy has an important effect on the geometry, barrier height, and vibrational frequencies of the transition state. The final calculated values for the forward and reverse classical barrier heights are 7.4 and 20.6 kcal/mol, respectively. We have used these with interpolated canonical variational transition state theory and the centrifugal-dominant small-curvature tunneling approximation, including information at the reactants, products, transition state, and two other points along the minimum energy path, to predict the rate constants for the above reaction in the temperature range from 223 to 2400 K. The calculated rate constants agree well with experiment over a wide temperature range.

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U2 - 10.1063/1.465401

DO - 10.1063/1.465401

M3 - Article

AN - SCOPUS:32544451460

VL - 99

SP - 1013

EP - 1027

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 2

ER -