Ab initio transition state theory calculations of the reaction rate for OH+CH sub 4 r arrow H sub 2 O+CH sub 3

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459103· OSTI ID:6707757

Truong, T N; Truhlar, D G ^[1]

---

1. Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemistry Minnesota Univ., Minneapolis, MN (USA). Supercomputer Inst.

We have carried out {ital ab} {ital initio} calculations using Moller--Plesset perturbation theory, scaling all correlation energy in second order (MP-SAC2) with several large basis sets, for the reaction OH+CH{sub 4}{r arrow}H{sub 2}O+CH{sub 3}. We found that correlation has a large effect on the geometry, barrier height, and vibrational frequencies of the transition state. The final calculated values, obtained with a correlation-balanced basis set, for the forward and reverse classical barrier heights are 7.9 and 21.2 kcal/mol, respectively. We have used these with transition state theory and an Eckart model for semiclassical tunneling calculations of the rate constants for the above reaction in the temperature range from 200 to 2000 K. We found that the present model, which requires information only at the reactants, transition state, and products, predicts rate constants of the same order of magnitude as the experimental data for this wide temperature range.

• OSTI ID: 6707757
• Journal Information: Journal of Chemical Physics; (USA), Vol. 93:3; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROXYL RADICALS
CHEMICAL REACTION KINETICS
METHANE
COMBUSTION
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
PERTURBATION THEORY
ALKANES
CHEMICAL REACTIONS
CORRELATIONS
HYDROCARBONS
KINETICS
ORGANIC COMPOUNDS
OXIDATION
RADICALS
REACTION KINETICS
THERMOCHEMICAL PROCESSES
400201* - Chemical & Physicochemical Properties