Bottlenecks intramolecular dividing surface

This hnding concerning quantum transport in classically chaotic systems sheds new light on quantum effects in unimolecular reaction dynamics. For example, one expects that intramolecular bottlenecks associated with canton, if treated quantum mechanically, would be more effective than in a classical statistical theory even when nh is smaller than the reaction flux crossing the intramolecular dividing surface. Clearly, it would be interesting to examine realistic molecular systems in a similar fashion. 

Figure 17. The Poincare surface of section for T-shaped Hel2 with the initial vibrational state of I2 given by v = 10. Two bottlenecks to intramolecular energy transfer are shown, together with a 5 1 resonance zone and the dissociation dividing surface. From top to bottom the figures show how trajectories escape the first and then the second intramolecular botdenecks. The bottom panel shows trajectories passing the separatrix for dissociation. [From M. J. Davis and S. K. Gray, J. Chem. Phys. 84, 5389 (1986).]...

To calculate the normalization constant Na in feintra Zhao and Rice proceeded as follows. Assuming that the system is prepared in a state with all the phase-space points inside the intramolecular bottleneck dividing surface, then the density of these phase-space points can be written as... 

Figure 19. A schematic plot of the ideal bottlenecks on the Poincare surface of section for van der Waals molecule predissociation. R is the van der Waals bond length and P is the conjugate momentum. 5i is the intramolecular bottleneck dividing surface and S2 is the intermoleculear bottleneck dividing surface.

In model No. 1 only the intermolecular dividing surface is considered. Model No. 2 includes bottleneck effects in intramolecular energy transfer. 

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