Phase Space Structures Explain Hydrogen Atom Roaming in Formaldehyde Decomposition.
We re-examine the prototypical roaming reaction--hydrogen atom roaming in formaldehyde decomposition--from a phase space perspective. Specifically, we address the question "why do trajectories roam, rather than dissociate through the radical channel?" We describe and compute the phase space structures that define and control all possible reactive events for this reaction, as well as provide a dynamically exact description of the roaming region in phase space. Using these phase space constructs, we show that in the roaming region, there is an unstable periodic orbit whose stable and unstable manifolds define a conduit that both encompasses all roaming trajectories exiting the formaldehyde well and shepherds them toward the H2···CO well.
School of Mathematics, University of Bristol , Bristol BS8 1TW, United Kingdom.
Frédéric A L
FA
Mauguière
School of Mathematics, University of Bristol , Bristol BS8 1TW, United Kingdom.
Peter
P
Collins
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853, United States.
Zeb C
ZC
Kramer
School of Chemistry, Cardiff University , Cardiff CF10 3AT, United Kingdom.
Barry K
BK
Carpenter
Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853, United States.
Gregory S
GS
Ezra
Department of Chemistry, University of Crete and Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas , Iraklion 711 10, Crete, Greece.
Stavros C
SC
Farantos
School of Mathematics, University of Bristol , Bristol BS8 1TW, United Kingdom.
Stephen
S
Wiggins
NHIM; formaldehyde; periodic orbits; phase space; roaming reactions; transition state theory