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NATPS: Nonadiabatic Transition Path Sampling Using the Time-Reversible Mapping Approach to Surface Hopping
Xiran Yang1,2,3, Madlen Maria Reiner2,4,5, Brigitta Bachmair1,2,3
1Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
The Journal of Physical Chemistry Letters
|May 13, 2026
Summary
We developed nonadiabatic transition path sampling (NATPS), a novel computational method for simulating rare nonadiabatic events in photochemistry. NATPS efficiently generates reactive trajectories, reducing computational cost for studying excited-state dynamics.
Area of Science:
- Computational Chemistry
- Photochemistry
- Quantum Dynamics
Background:
- Nonadiabatic events are crucial in photochemistry but challenging to simulate due to computational demands and stochasticity.
- Existing methods for simulating excited-state dynamics often struggle with efficiency and accuracy for rare events.
Purpose of the Study:
- To introduce a deterministic and time-reversible method for simulating nonadiabatic dynamics.
- To enable the application of transition path sampling (TPS) to excited-state processes.
- To develop a new computational approach for studying rare nonadiabatic events.
Main Methods:
- Developed a deterministic and time-reversible implementation of nonadiabatic dynamics based on the Mapping Approach to Surface Hopping (MASH).
- Integrated MASH with the Transition Path Sampling (TPS) framework to create Nonadiabatic Transition Path Sampling (NATPS).
- Established conditions for path ensemble sampling, including time reversibility and detailed balance.
Main Results:
- NATPS efficiently generates ensembles of reactive trajectories for electronically coupled potential energy surfaces.
- The method provides mechanistic insights into nonadiabatic pathways.
- Significantly reduced computational effort compared to brute-force simulations and forward-flux sampling.
Conclusions:
- NATPS offers a powerful and efficient approach for studying nonadiabatic dynamics in photochemistry.
- This method facilitates the investigation of rare events in excited-state processes.
- NATPS enhances our ability to understand complex photochemical mechanisms computationally.
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