Dynamics and decay rates of a time-dependent two-saddle system

Area of Science:

• Chemical Dynamics
• Theoretical Chemistry
• Reaction Rate Theory

Background:

• Transition state theory (TST) is a key framework for analyzing chemical reaction dynamics.
• Standard TST effectively handles single time-dependent saddle points but faces challenges with multiple driven saddles due to complex phase space structures.
• Understanding reaction dynamics in systems with multiple saddles is crucial for accurately predicting reaction rates.

Purpose of the Study:

• To develop a method for constructing an approximately recrossing-free dividing surface for systems with multiple driven saddles.
• To present and discuss methods for calculating instantaneous (time-resolved) decay rates of activated complexes in such systems.
• To address the limitations of traditional TST in complex, time-dependent reaction environments.

Main Methods:

• Construction of an approximately recrossing-free dividing surface utilizing the normally hyperbolic invariant manifold.
• Application of the developed surface to a time-dependent two-saddle model system.
• Development and application of multiple methods for calculating time-resolved decay rates.

Main Results:

• Successfully constructed an approximately recrossing-free dividing surface for a time-dependent two-saddle system.
• Presented multiple methods for obtaining instantaneous decay rates, providing insights into the dynamics of the activated complex.
• Demonstrated a viable approach to overcome the challenges posed by fractal-like phase space structures in multi-saddle systems.

Conclusions:

• The developed method offers a robust framework for analyzing reaction dynamics in systems with multiple driven saddles.
• The approach enables accurate calculation of time-resolved decay rates, improving upon traditional TST limitations.
• This work advances the understanding and computational treatment of complex chemical reactions governed by multi-saddle dynamics.