Collinear reactive scattering resonances

Romelt, J. (1983). Prediction and interpretation of collinear reactive scattering resonances by the diagonal corrected vibrational adiabatic hyperspherical model, Chem. Phys. 79, 197-209. 

DIVAH model for collinear reactive scattering resonances... 

Poliak, E. and Child, M.S. (1981). A simple classical prediction of quanta resonances in collinear reactive scattering, Chem. Phys. 60, 23-32. 

E. Poliak and M. S. Child, Chem. Phys., 60, 23 (1981). A Simple Prediction of Quantal Resonances in Collinear Reactive Scattering. 

A. Kuppermann and J. P. Dwyer, A simple model of dynamic resonances in collinear reactive scattering, in "Electronic and Atomic Collisions, Abstracts of Contributed Papers, XIth... 

International Conference on the Physics of Electronic and Atomic Collisions, Kyoto , K. Takayanagi and N. Oda, eds., The Society for Atomic Collision Research, Japan (1979), pp. 888-889 J. P. Dwyer and A. Kuppermann, Resonances in collinear reactive scattering A simple hyperspherical coordinate model, manuscript in preparation. 

The F + H2 — HF + FI reaction is one of the most studied chemical reactions in science, and interest in this reaction dates back to the discovery of the chemical laser.79 In the early 1970s, a collinear quantum scattering treatment of the reaction predicted the existence of isolated resonances.80 Subsequent theoretical investigations, using various dynamical approximations on several different potential energy surfaces (PESs), essentially all confirmed this prediction. The term resonance in this context refers to a transient metastable species produced as the reaction occurs. Transient intermediates are well known in many kinds of atomic and molecular processes, as well as in nuclear and particle physics.81 What makes reactive resonances unique is that they are not necessarily associated with trapping... 

G.C. Schatz, A. Kuppermann, Dynamical resonances in collinear, coplanar, and three-dimensional quantum mechanical reactive scattering, Phys. Rev. Lett. 35 (1975) 1266. 

A scattering calculation gives the most complete description of resonances in reactive and non-reactive systems. However, if the resonances are the major features of interest a more direct approach to obtain them is desirable. A number of such aproaches exist and are reviewed in this volume and in the following sections of this paper. These have been applied mainly to non-reactive systems, however, they are beginning to be used in reactive systems. Thus far they have been applied to collinear reactive systems where their accuracy is being tested. The status of these calculations is discussed in a paper by Garrett et al. in this volume. 

The main objective of any theory is to be able to understand and predict the results of experiments. Since the world is three dimensional one cannot limit oneself to the study of collinear systems. In section IV we show how the collinear analysis based on periodic orbits may be generalised to three dimensional systems.We provide a 3D adiabatic transition state theory which is used to analyse numerical computations as well as experimental results. A 3D analysis of quantal resonances predicts that one should hope that quantal resonances will provide a new spectroscopy of transition states. A discussion of the future role of periodic orbits and reactive scattering is given in section V. 

Early the QCT [106] and collinear quantum reactive scattering studies [113] revealed their distinct difference for predicting the F -f H2 reaction, especially for the F -I- HD reaction where reactive resonances played a big role. Subsequent 3D quantum scattering calculations by Wyatt and coworkers [77,78] and a variety of 3D quantum models confirmed the existence of the resonance, thereby stimulating further experiments on F - - H2 and its isotopic analogs and finally leading to the molecular beam studies ofNeumark and coworkers [91-94] which proved important hints that resonances play a role in this reaction. 

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