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Title: Collision dynamics of symmetric top molecules: A comparison of the rotationally inelastic scattering of CD{sub 3} and ND{sub 3} with He

We compare rotationally inelastic scattering of deuterated methyl radicals (CD{sub 3}) and ammonia (ND{sub 3}) in collisions with helium using close-coupling quantum-mechanical scattering calculations performed with ab initio potential energy surfaces (PESs). The theoretical methods have been rigorously tested against angle-resolved experimental measurements obtained using crossed molecular beam apparatuses in combination with velocity map imaging [O. Tkáč, A. G. Sage, S. J. Greaves, A. J. Orr-Ewing, P. J. Dagdigian, Q. Ma, and M. H. Alexander, Chem. Sci. 4, 4199 (2013); O. Tkáč, A. K. Saha, J. Onvlee, C.-H. Yang, G. Sarma, C. K. Bishwakarma, S. Y. T. van de Meerakker, A. van der Avoird, D. H. Parker, and A. J. Orr-Ewing, Phys. Chem. Chem. Phys. 16, 477 (2014)]. Common features of the scattering dynamics of these two symmetric top molecules, one closed-shell and the other an open-shell radical, are identified and discussed. Two types of anisotropies in the PES influence the interaction of an atom with a nonlinear polyatomic molecule. The effects of these anisotropies can be clearly seen in the state-to-state integral cross sections out of the lowest CD{sub 3} rotational levels of each nuclear spin symmetry at a collision energy of 440 cm{sup −1}. Similarities and differences inmore » the differential cross sections for the ND{sub 3}–He and CD{sub 3}–He systems can be linked to the coupling terms derived from the PESs which govern particular initial to final rotational level transitions.« less
Authors:
;  [1] ;  [2] ;  [3] ; ;  [4]
  1. School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS (United Kingdom)
  2. Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685 (United States)
  3. Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2021 (United States)
  4. Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen (Netherlands)
Publication Date:
OSTI Identifier:
22253305
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMMONIA; ANISOTROPY; COLLISIONS; COUPLING; DEUTERIDES; DIFFERENTIAL CROSS SECTIONS; INELASTIC SCATTERING; INTEGRAL CROSS SECTIONS; INTERACTIONS; METHYL RADICALS; MOLECULAR BEAMS; POTENTIAL ENERGY; QUANTUM MECHANICS