Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Chemistry
Mixed Quantum/Classical Theory Of Rotationally And Vibrationally Inelastic Scattering In Space-Fixed And Body-Fixed Reference Frames, Alexander Semenov, Dmitri Babikov
Mixed Quantum/Classical Theory Of Rotationally And Vibrationally Inelastic Scattering In Space-Fixed And Body-Fixed Reference Frames, Alexander Semenov, Dmitri Babikov
Chemistry Faculty Research and Publications
We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated …
Equivalence Of The Ehrenfest Theorem And The Fluid-Rotor Model For Mixed Quantum/Classical Theory Of Collisional Energy Transfer, Alexander Semenov, Dmitri Babikov
Equivalence Of The Ehrenfest Theorem And The Fluid-Rotor Model For Mixed Quantum/Classical Theory Of Collisional Energy Transfer, Alexander Semenov, Dmitri Babikov
Chemistry Faculty Research and Publications
The theory of two seemingly different quantum/classical approaches to collisional energy transfer and ro-vibrational energy flow is reviewed: a heuristic fluid-rotor method, introduced earlier to treat recombination reactions[M. Ivanov and D. Babikov, J. Chem. Phys.134, 144107 (Year: 2011)10.1063/1.3576103], and a more rigorous method based on the Ehrenfest theorem. It is shown analytically that for the case of a diatomic molecule + quencher these two methods are entirely equivalent. Notably, they both make use of the average moment of inertia computed as inverse of average of inverse of the distributed moment of inertia. Despite this equivalence, each of the two formulations …