Digital.CSIC > Ciencia y Tecnologías Físicas > Centro de Física Miguel A. Catalán - Instituto de Física Fundamental (CFMAC-IFF) > (CFMAC-IFF) Artículos >




Open Access item F+OH reactive collisions on new excited 3A'' and 3A' potential-energy surfaces

Authors:Gómez Carrasco, Susana
Roncero, Octavio
González-Sánchez, Lola
Hernández, M. Luz
Alvariño, José M.
Paniagua, Miguel
Aguado, Alfredo
Keywords:Fluorine, Oxygen compounds, Atom-molecule reactions, Potential energy surfaces, Reaction kinetics theory, Reaction rate constants, Ab initio calculations, [PACS] Atom and radical chemical reactions; chain reactions, molecule-molecule reactions, [PACS] Potential energy surfaces for chemical reactions, [PACS] Transition state theory and statistical theories of rate constants (chemical kinetics), [PACS] Chemical rate constants, reaction cross sections, and activation energies
Issue Date:22-Sep-2005
Publisher:American Institute of Physics
Citation:Journal of Chemical Physics 123(11): 114310 (2005)
Abstract:Global three-dimensional adiabatic potential-energy surfaces for the excited 2(3)A'' and 1(3)A' triplet states of OHF are obtained to study the F(2P)+OH(2Π)O(3P)+HF(1Σ+) reaction. Highly accurate ab initio calculations are obtained for the two excited electronic states and fitted to analytical functions with small deviations. The reaction dynamics is studied using a wave-packet treatment within a centrifugal sudden approach, which is justified by the linear transition state of the two electronic states studied. The reaction efficiency presents a marked preference for perpendicular orientation of the initial relative velocity vector and the angular momentum of the OH reagent, consistent in the body-fixed frame used with an initial collinear geometry which facilitates the access to the transition state. It is also found that the reaction cross section presents a rather high threshold so that, in an adiabatic picture, the two excited triplet states do not contribute to the rate constant at room temperature. Thus, only the lowest triplet state leads to reaction under these conditions and the simulated rate constants are too low as compared with the experimental ones. Such disagreement is likely to be due to nonadiabatic transitions occurring at the conical intersections near the transition state for this reaction.
Description:13 pages, 10 figures, 5 tables.-- PACS nrs.: 82.30.Cf; 82.20.Kh; 82.20.Db; 82.20.Pm.
Publisher version (URL):http://dx.doi.org/10.1063/1.2046669
Appears in Collections:(CFMAC-IFF) Artículos

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.