Thumbnail
Access Restriction
Open

Author Dzegilenko, F. N. ♦ Bowman, J. M.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ HYDROXYL RADICALS ♦ CHEMICAL REACTION KINETICS ♦ CARBON MONOXIDE ♦ DEGREES OF FREEDOM ♦ ANGULAR MOMENTUM ♦ ROTATIONAL STATES ♦ BENDING ♦ CALCULATION METHODS ♦ REACTION RATES ♦ POTENTIAL ENERGY SURFACES
Abstract Two reduced dimensionality theories are used to calculate the thermal rate constant for the OH+CO{r_arrow}H+CO{sub 2} reaction. The standard theory employs energy-shift approximations to extract the full six degree-of-freedom quantum rate constant for this reaction from the previous two degree-of-freedom (2-DOF) quantum calculations of Hernandez and Clary [M.I. Hernandez and D.C. Clary, J. Chem. Phys. {bold 101}, 2779 (1994)]. Three extra bending modes and one extra {open_quote}{open_quote}spectator{close_quote}{close_quote} CO stretch mode are treated adiabatically in the harmonic fashion. The parameters of the exit channel transition state are used to evaluate the frequencies of those additional modes. A new reduced dimensionality theory is also applied to this reaction. This theory explicitly addresses the finding from the 2-DOF calculations that the reaction proceeds mainly via complex formation. A J-shifting approximation has been used to take into account the initial states with non-zero values of total angular momentum in both reduced dimensionality theories. Cumulative reaction probabilities and thermal rate constants are calculated and compared with the previous quasiclassical and reduced dimensionality quantum calculations and with experiment. The rate constant from the new reduced dimensionality theory is between a factor of 5 and 100 times smaller than the statistical transition state theory result, and is in much better agreement with experiment. {copyright} {ital 1996 American Institute of Physics.}
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-08-01
Publisher Place United States
Journal Journal of Chemical Physics
Volume Number 105
Issue Number 6


Open content in new tab

   Open content in new tab