Semiclassical treatment of atom-asymmetric rotor collisions; rotational excitation of formaldehyde at low energies
- 15 October 1974
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 61 (8), 3155-3163
- https://doi.org/10.1063/1.1682471
Abstract
The formalism necessary for the application of ``classical S‐matrix'' theory to collisions of an atom with a rigid asymmetric rotor is derived. This is applied to rotational excitation of formaldehyde by H2 (taken to be spherically symmetric) at energies from 10 to 15°K. Classical Monte Carlo trajectory calculations were also carried out for the same system in the energy range 10–40°K. The results support the proposal of Townes and Cheung that a collisional mechanism is responsible for the 111 →110 anomalous absorption of formaldehyde in cool interstellar dust clouds.Keywords
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