Journal ArticleDOI
Rotational transfer, an angular momentum model
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TLDR
In this paper, it was shown that the probability of collision induced rotational transfer (RT) is controlled by the factors that control the angular momentum (AM) change, and that such a calculation leads to an exponential fall of RT probabilities with transferred AM, a consequence of the radial dependence of the repulsive part of the intermolecular potential.Abstract:
We have re‐examined critical experiments on collision induced rotational transfer (RT) and conclude that the probability of RT is controlled by the factors that control the probability of angular momentum (AM) change. The probability of energy change seems less important in this respect. In the light of this we suggest a model for RT in which the probability of AM change is calculated directly and present a formalism for this purpose. We demonstrate that such a calculation leads to an exponential‐like fall of RT probabilities with transferred AM, a consequence of the radial dependence of the repulsive part of the intermolecular potential. Thus in this AM model, the exponential gap law has a simple physical origin. The AM model we describe may be used as the basis of an inversion routine through which it is possible to convert RT data into a probability density of the repulsive anisotropy. Through this model therefore it is possible to relate experimental RT data directly to the forces that are responsible for rotational transfer. The hard ellipse model is used in this work to relate calculated anisotropies to a form that includes an isotropic component. The result is a representation of the intermolecular potential through which new insights into the RT process are gained.read more
Citations
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Journal ArticleDOI
A fitting law for rotational transfer rates: An angular momentum model with predictive power
TL;DR: In this paper, a law for state-to-state rotational transfer (RT) in diatomic molecules based on the angular momentum (AM) theory proposed by McCaffery et al. was formulated.
Journal ArticleDOI
A new approach to molecular collision dynamics
TL;DR: In this article, a model of collision and reaction dynamics is developed from two basic equations, one representing the conservation of angular momentum and the other conservation of energy, and the model is used to predict the outcome of the elementary collisions of physical and chemical change.
Journal ArticleDOI
Direct measurement of thermal rate constants for state‐to‐state rotational energy transfer in collisions of CN(X 2Σ+, v=2, N) with He
TL;DR: In this article, it was shown that 2/3 of the value of the total removal rate constant corresponds to changes in the rotational quantum number of the violet system and a strong propensity is evident which favors even changes in N for ε ≥ 4.
Journal ArticleDOI
Rotationally inelastic scattering of jet cooled h2o with ar : state-to-state cross sections and rotational alignment effects
TL;DR: In this article, column-integrated densities of H2O in both initial and final scattering states were monitored via direct absorption of narrow bandwidth (Δν≈0.0001 cm−1) infrared light from a continuous wave (cw) F-center laser.
Journal ArticleDOI
Inelastic scattering of OH(X 2Π) with Ar and He: a combined polarization spectroscopy and quantum scattering study
TL;DR: The measurement of k(DEP) may provide a useful new tool that is more sensitive to the form of the long-range part of the intermolecular potential than rotational state-changing collisions.
References
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Book
Molecular Reaction Dynamics and Chemical Reactivity
TL;DR: In this article, the authors deal with the molecular-level mechanism of elementary chemical reactions, and progress from the basic principles of physical chemistry to up-to-date research results to provide an understanding of chemical reactivity and physical rate processes from the fundamental point of view of atom-atom interactions all the way to the description of catalysis.
Journal ArticleDOI
The Theory of Scattering by a Rigid Rotator
A. M. Arthurs,Alexander Dalgarno +1 more
TL;DR: A theory of scattering by a rigid rotator in which the coupling between the different energy levels of the rotator is taken into account is formulated and explicit expressions, which do not depend upon the magnetic quantum numbers, are obtained for various elastic and inelastic cross-sections as discussed by the authors.
Journal ArticleDOI
Mechanism of Rotational Relaxation
J. C. Polanyi,K. B. Woodall +1 more
TL;DR: In this paper, a model of the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J, is presented.
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