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Reaction Path-Resolved Quantum Transition State Framework Using Hyperspherical (APH) Coordinates: The Geometric Phase
Yajian Shu1,2, Hailin Zhao1, Zhigang Sun1
1State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
The Journal of Physical Chemistry. A
|January 21, 2025
Summary
A new quantum transition state framework simplifies calculating reaction pathways for atom-diatom reactions. This method reveals geometric phase effects are minor in H + H2 reactions, but may increase with rotational excitation.
Area of Science:
- Quantum Chemistry
- Chemical Dynamics
- Theoretical Chemistry
Background:
- Calculating reaction dynamics is crucial for understanding chemical reactivity.
- Atom-diatom reactions present complex quantum mechanical challenges.
- Previous models often struggled to directly compute reaction path-resolved scattering matrices.
Purpose of the Study:
- To develop a quantum transition state framework for calculating reaction path-resolved scattering matrices.
- To directly compute scattering matrices for atom-diatom reactions in hyperspherical coordinates.
- To investigate the role of specific reaction pathways and geometric phase effects.
Main Methods:
- Developed a quantum transition state framework.
- Utilized hyperspherical (APH) coordinates for calculations.
- Performed detailed calculations for the H + H2 reaction at J = 0, 1, 2.
Main Results:
- The framework successfully calculates reaction path-resolved scattering matrices.
- Encircling reaction paths were found to have a negligible role in the H + H2 reaction.
- Geometric phase effects were observed to be minor, even above the conical intersection minimum.
Conclusions:
- The developed quantum transition state framework is effective for analyzing reaction dynamics.
- Geometric phase effects are less significant than previously thought for this specific reaction system.
- These effects may become more pronounced with increased rotational excitation of reactants and products.
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