Angular distributions rotating linear model

Reactive Resonances and Angular Distributions in the Rotating Linear Model... 

We use the Bending-Corrected Rotating Linear Model (BCRLM) to Investigate In detail the way In which resonances may affect the angular distribution of reaction products. Using a lifetime matrix method, we separate the resonant and direct parts of the S matrix, and from the direct part we obtain angular distributions In the absence of the resonance. When applied to the F+H2(v= 0) HF(v =2)+H reaction on the... 

In this paper, we will present a detailed analysis of the way In which resonances may affect the angular distribution of the products of reactive collisions. To do this, we have used an approximate three-dimensional (3D) quantum theory of reactive scattering (the Bending-Corrected Rotating Linear Model, or BCRLM) to generate the detailed scattering Information (S matrices) needed to compute the angular distribution of reaction products. We also employ a variety of tools, notably lifetime matrix analysis, to characterize the Importance of a resonance mechanism to the dynamics of reactions. 

Coupled channel methods for colllnear quantum reactive calculations are sufficiently well developed that calculations can be performed routinely. Unfortunately, colllnear calculations cannot provide any Insight Into the angular distribution of reaction products, because the Impact parameter dependence of reaction probabilities Is undefined. On the other hand, the best approximate 3D methods for atom-molecule reactions are computationally very Intensive, and for this reason. It Is Impractical to use most 3D approximate methods to make a systematic study of the effects of potential surfaces on resonances, and therefore the effects of surfaces on reactive angular distributions. For this reason, we have become Interested In an approximate model of reaction dynamics which was proposed many years ago by Child (24), Connor and Child (25), and Wyatt (26). They proposed the Rotating Linear Model (RLM), which Is In some sense a 3D theory of reactions, because the line upon which reaction occurs Is allowed to tumble freely In space. A full three-dimensional theory would treat motion of the six coordinates (In the center of mass) associated with the two... 

Thus, the observed trend in lifetimes — (C2H )2 C2H HCl <excited mode, the amount of linear and angular momentum which must be incorporated into fragment motion, and the overall number of product channels available. This inferred mechanism is subject to further tests. These include measurements of product velocity and rotational distributions. Real time measurements of either the population in the initially pumped level or the appearance of product fragments would be of great significance. 

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