Speaker : Turgay Uzer, Regents' Professor Center for Nonlinear Science, School of Physics,
Georgia Institute of Technology, Atlanta, Georgia 30332-0430,
U.S.A.
Date : 2004-07-09 15:00
Venue :
Conference Hall 322, ITP/理论物理所322报告厅
Abstract : The notion of a transition state is one of the grand unifying concepts in chemistry1. Many theories of chemical reactions explicitly assume that once reactants pass through the transition state then they cannot return2. This “no-recrossing rule” serves to define the transition state and is a necessary assumption in transition state theory3,4. Despite its ubiquity in chemistry it is only recently, however, that the existence of the transition state in more than two degrees-of-freedom (dof) has been proved5. Furthermore no general theory has existed for actually finding the transition state6. Here, combining methods of celestial mechanics with recent advances in dynamical systems theory,7 we provide a theory which is rigorously valid in an arbitrary number of dof. Equally important, advances in computational power make the method applicable in practice for large systems. Knowledge of the transition state – a phase space object - allows us to differentiate, with exquisite precision, between reactive and nonreactive molecular configurations wherever they lie in phase space. #@#@#@- Polanyi, J. C. and Zewail, A. H. Direct observation of the transition state. Acc. Chem. Res., 28, 119 – 132 (1995).#@#@
- Marcus, R.A. Skiing the reaction rate slopes. Science, 256, 1523 -1524 (1992).#@#@
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- Miller, W.H., Spiers Memorial Lecture. Quantum and semiclassical theory of reaction rates. Farad. Discuss., 110, 1 - 21 (1998).#@#@
- Wiggins, S., Wiesenfeld, L., Jaffé, C., and Uzer, T. Impenetrable barriers in phase-space. Phys. Rev. Lett., 86, 5478 - 5481 (2001).#@#@
- Komatsuzaki, T and Berry, R. S. Regularity in chaotic reaction paths III: Ar6 local invariance at the reaction bottleneck. J. Chem. Phys., 115, 4105 - 4117, (2000).#@#@
- Uzer, T., Jaffé, C., Palacián, J., Yanguas, P., and Wiggins, S. The geometry of reaction dynamics. Nonlinearity, 15, 957 - 992 (2002).#@
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