Regular and Chaotic Dynamics

, Volume 23, Issue 1, pp 60–79 | Cite as

Dynamics on the Double Morse Potential: A Paradigm for Roaming Reactions with no Saddle Points

  • Barry K. CarpenterEmail author
  • Gregory S. Ezra
  • Stavros C. Farantos
  • Zeb C. Kramer
  • Stephen Wiggins


In this paper we analyze a two-degree-of-freedom Hamiltonian system constructed from two planar Morse potentials. The resulting potential energy surface has two potential wells surrounded by an unbounded flat region containing no critical points. In addition, the model has an index one saddle between the potential wells. We study the dynamical mechanisms underlying transport between the two potential wells, with emphasis on the role of the flat region surrounding the wells. The model allows us to probe many of the features of the “roaming mechanism” whose reaction dynamics are of current interest in the chemistry community.


Double Morse potential phase space structure dynamics periodic orbit roaming 

MSC2010 numbers

37Axx 37Jxx 37Nxx 37N20 


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Copyright information

© Pleiades Publishing, Ltd. 2018

Authors and Affiliations

  • Barry K. Carpenter
    • 1
    Email author
  • Gregory S. Ezra
    • 2
  • Stavros C. Farantos
    • 3
  • Zeb C. Kramer
    • 4
  • Stephen Wiggins
    • 5
  1. 1.School of ChemistryCardiff UniversityCardiffUK
  2. 2.Department of Chemistry and Chemical BiologyCornell UniversityIthacaUSA
  3. 3.Institute of Electronic Structure and Laser, Foundation for Research and Technology–Hellas, and Department of ChemistryUniversity of CreteIraklionGreece
  4. 4.Department of Chemistry and BiochemistryLa Salle UniversityPhiladelphiaUSA
  5. 5.School of MathematicsUniversity of BristolBristolUK

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