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Communication: transition state theory for dissipative systems without a dividing surface.

F Revuelta¹, Thomas Bartsch, R M Benito

¹Grupo de Sistemas Complejos, and Dep. de Física y Mecánica, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain.

The Journal of Chemical Physics

|March 10, 2012

Summary

This study identifies a geometric structure to precisely determine reactive trajectories in stochastically driven systems. This leads to an exact, dividing surface-independent rate formula for condensed phase reactions.

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Area of Science:

Chemical kinetics
Reaction dynamics
Statistical mechanics

Background:

Transition state theory (TST) is fundamental to reaction dynamics.
TST relies on identifying a dividing surface for reactive trajectories.
This assumption is often violated in environmentally coupled systems, leading to inaccurate rate calculations.

Purpose of the Study:

To identify the geometric structure that unambiguously determines reactive trajectories in stochastically driven systems.
To develop a rate formula for condensed phase reactions that is independent of the dividing surface and exact.

Main Methods:

Analysis of the phase space of a stochastically driven system near an energetic barrier.
Identification of a unique geometric structure governing reactive trajectories.

Main Results:

A geometric structure was identified that precisely defines reactive trajectories.
A novel rate formula was derived for condensed phase reactions.
The new formula is independent of the dividing surface choice and yields exact results.

Conclusions:

The limitations of traditional transition state theory in complex systems are addressed.
A more robust method for calculating reaction rates in condensed phases is presented.
This work offers a significant advancement in understanding and quantifying chemical reaction dynamics.