Chapter 5. Intramolecular Dynamics Along Isomerization and Dissociation Pathways

  1. M. Toda6,
  2. T. Komatsuzaki7,
  3. T. Konishi8,
  4. R. S. Berry9 and
  5. S. A. Rice10
  1. Marc Joyeux1,
  2. Sergy Yu. Grebenshchikov2,
  3. Jens Bredenbeck2,†,
  4. Reinhard Schinke2 and
  5. Stavros C. Farantos3,4

Published Online: 27 JAN 2005

DOI: 10.1002/0471712531.ch5

Geometric Structures of Phase Space in Multidimensional Chaos: Applications to Chemical Reaction Dynamics in Complex Systems, Volume 130

Geometric Structures of Phase Space in Multidimensional Chaos: Applications to Chemical Reaction Dynamics in Complex Systems, Volume 130

How to Cite

Joyeux, M., Grebenshchikov, S. Yu., Bredenbeck, J., Schinke, R. and Farantos, S. C. (2005) Intramolecular Dynamics Along Isomerization and Dissociation Pathways, in Geometric Structures of Phase Space in Multidimensional Chaos: Applications to Chemical Reaction Dynamics in Complex Systems, Volume 130 (eds M. Toda, T. Komatsuzaki, T. Konishi, R. S. Berry and S. A. Rice), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471712531.ch5

Editor Information

  1. 6

    Physics Department, Nara Women's University, Nara, 630-8506, Japan

  2. 7

    Nonlinear Science Laboratory, Department of Earth and Planetary Sciences, Faculty of Science, Kobe University, Nada, Kobe, 657-8501, Japan

  3. 8

    Department of Physics, Nagoya University, Nagoya, 464-8602, Japan

  4. 9

    Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA

  5. 10

    Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 USA

Author Information

  1. 1

    Laboratoire de Spectrométrie Physique (CNRS UMR 5588), Université Joseph Fourier, Grenoble 1, F-38402 St. Martin d'Hères Cedex, France

  2. 2

    Max-Planck-Institüt für Strömungsforschung, D-37073 Göttingen, Germany

  3. 3

    Institute of Electronic Structure and Laser Foundation for Research and Technology, Hellas, Greece

  4. 4

    Department of Chemistry, University of Crete, Iraklion 711 10, Crete, Greece

  1. Physikalisch-Chemisches Institüt, Universität Zürich, CH-8057 Zürich, Switzerland

Publication History

  1. Published Online: 27 JAN 2005
  2. Published Print: 21 JAN 2005

Book Series:

  1. Advances in Chemical Physics

Book Series Editors:

  1. Stuart A. Rice

Series Editor Information

  1. Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 USA

ISBN Information

Print ISBN: 9780471711582

Online ISBN: 9780471712534

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Keywords:

  • intramolecular dynamics;
  • non-linear dynamics;
  • vibrations;
  • isomerization;
  • dissociation;
  • canonical perturbation theory;
  • Fermi resonance;
  • semi-classical quantization;
  • periodic orbits;
  • bifurcations

Summary

We discuss the vibrational motion of highly excited triatomic molecules which can either isomerize or dissociate. The changes of the classical phase space with increasing energy and the consequences for the quantum mechanical spectrum are particularly emphasized. The molecules which will be highlighted are HCN, HCP, HOCl, and HOBr. Exact quantum mechanical calculations using realistic potential energy surfaces are contrasted with classical mechanics and semiclassical calculations, and various methods are applied to extract dynamics information from the spectra: canonical perturbation theory, adiabatic separation and periodic orbits. For HCN, there is no near resonance between the fundamental frequencies, and it is shown how canonical perturbation theory can be used to find coordinates in which the Hamiltonian is nearly separable. The other systems are characterized by a pronounced 1:2 Fermi resonance. The interplay between this resonance and the strong anharmonicity along the reaction (isomerization or dissociation) path leads to saddle-node bifurcations. At these bifurcations, new types of molecular motion abruptly come into existence, which gradually advance the molecule along the reaction path. Saddle-node bifurcations are responsible for the complexity of the spectra for HCP, HOCl, and HOBr at high energies.