Quantum mechanical calculation of the rate constant for the reaction H+O{sub 2}{r_arrow}OH+O
- Laboratoire Structure et Dynamique des Systemes Moleculaires et Solides (UMR 5636), CC 014, Universite des Sciences et Techniques du Languedoc, 34095Montpellier Cedex 05 (France)
- Department of Chemistry, University of California, and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720-1460 (United States)
Quantum rate calculations for the H+O{sub 2}{r_arrow}HO+O combustion reaction, as well as for the reverse reaction, are reported. Using the DMBE IV potential energy surface, the cumulative reaction probability N{sub 0}(E) has been directly computed for total angular momentum J=0, by means of the Seideman, Manthe and Miller Lanczos-based absorbing boundary condition method [J. Chem. Phys. {bold 96}, 4412 (1992); {bold 99}, 3411 (1993)]. Special attention has been paid to the definition of the molecular basis set, and to the sensitivity of the results to the absorbing potentials used in the asymptotic regions. The N{sub 0}(E) results show very good overall agreement with the coupled channel calculations of Pack {ital et al.} [J. Chem. Phys. {bold 102}, 5998 (1995)], although the highly oscillatory behavior just above threshold renders such a comparison difficult in that energy range. The behavior of the J{ne}0 cumulative reaction probability has been estimated from calculations using the J{sub z}-conserving approximation for J values in the range 10{endash}70. This allowed us to define which reference geometry should be used in the J-shifting approximation, in order to compute the cumulative reaction probability N{sub J}(E) for any J value. By imposing conservation of the total energy within this approximation, the rate constants are shown to display better agreement with the experimental results. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 613983
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 9 Vol. 108; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
Semiclassical calculation of cumulative reaction probabilities
Nonseparable transition state theory for nonzero total angular momentum: Implications for {ital J} shifting and application to the OH+H{sub 2} reaction