Resonant features in the energy dependence of the rate of ketene isomerization

Journal Article · Wed Nov 08 04:00:00 EST 1995 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.470204· OSTI ID:124788

Gezelter, J D; Miller, W H ^[1]

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1. Department of Chemistry, University of California, and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

Calculations of the microcanonical isomerization rates for vibrationally excited ketene are presented. The calculations utilize the quantum reactive scattering methodology of absorbing boundary conditions with a discrete variable representation to obtain the cumulative reaction probability for one form of ketene to isomerize via the oxirene intermediate, and were carried out with model 1-, 2-, and 3-degree-of-freedom potential energy surfaces constructed using {ital ab} {ital initio} data. Significant differences are seen in the energy dependent features of the microcanonical rate for the single mode and multi-mode potentials; e.g., the single mode potential exhibits tunneling resonances with widths of around 1 cm{sup {minus}1}, while the calculations involving more than one degree of freedom have additional resonant features that have widths around 10 cm{sup {minus}1} and also exhibit non-Breit--Wigner resonant line shapes. This suggests that many of the resonance features are best described as Feshbach (energy transfer, or dynamical) resonances that result because of a strongly bent region on the multi-mode potential energy surfaces. The calculated rates show reasonable qualitative agreement with the experimental results of Lovejoy and Moore [J. Chem. Phys. {bold 98}, 7846 (1993)]. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 124788
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 18 Vol. 103; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
BOUNDARY CONDITIONS
DEGREES OF FREEDOM
ENERGY DEPENDENCE
EXCITED STATES
ISOMERIZATION
KETENES
POTENTIAL ENERGY
RESONANCE
SCATTERING
SURFACES