Quantum dynamics of the collinear CsHH system

doi:10.1016/0009-2614(87)85175-8

Chemical Physics Letters

Volume 135, Issues 4–5, 10 April 1987, Pages 377-380

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Abstract

Quantum-mechanical transition probabilities for the collinear reaction Cs(nl)+HH(v) → CsH(v')+H have been computed using hyperspherical coordinates. The reaction involves a strong non-localized ionic-covalent electronic coupling. Large probabilities, with sharp resonance features, are obtained for nearly thermoneutral transitions such as Cs(6s) + HH(v= 6), Cs(7p) + HH(v = 0) → CsH(v' = 0) + H.

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The crossed beam experiments of L' Hermite et al.(1990–1991) on the reaction Cs ^∗ (7²P_$12$, $32$ ) + H₂ → CsH + H are simulated using the statistical algorithm RRKM-SA. Good agreement between the experimental and calculated rotational quantum number distributions as well as the fractional values of total energy in different degrees of freedom, are obtained. Quantization of vibrational energy is included in the otherwise classical calculations and is shown to be important. The reaction is found to be statistical but with a very strong dependence on the conservation of total angular momentum. In a so-called triangular plot it can be seen that it is the low total available energy that makes the angular momentum restrictions so important. This constraint also means that a considerable portion of the translational energy at the exit centrifugal barrier is instead found in molecular and complex rotational energy. Branching ratios are calculated for the reaction involving both Cs(7²P_$12$) and Cs(7²P_$32$) and good agreement with the approximate experimental values are obtained.
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Chemical Physics Letters

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Effects of L<inf>tot</inf>-conservation and quantization of vibrational energy in statistical simulations of the reaction Cs<sup>*</sup> (7<sup>2</sup>P<inf> 1 2</inf>, 3 2) + H<inf>2</inf> → CsH + H

Hyperspherical study of the reaction Cs+H<inf>2</inf>→CsH+H in the rotating linear model

Symmetry analysis of accurate H+H<inf>2</inf> resonances for low partial waves

Shape, feshbach, and "avoided crossing" resonances of the collinear F+DBr reaction

A proposal for the theoretical treatment of multi-electronic-state molecular dynamics: Hemiquantal dynamics with the whole dim basis (HWD). A test on the evolution of excited Ar<inf>3</inf><sup>+</sup> cluster ions

Hyperfine structure effect in the Cs(7P)+H<inf>2</inf> reaction. Experimental observation and theoretical interpretation