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Perturbative wave-packet spawning procedure for non-adiabatic dynamics in diabatic representation
1Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
The Journal of Chemical Physics
|March 22, 2013
Summary
This study introduces a novel wave-packet spawning method using perturbation theory for accurate population transfer calculations between electronic states. It provides a rigorous criterion for basis set expansion in quantum dynamics simulations.
Area of Science:
- Chemical Physics
- Quantum Dynamics
- Theoretical Chemistry
Background:
- Accurate simulation of non-adiabatic dynamics is crucial for understanding chemical reactions.
- Existing wave-packet propagation methods can struggle with adequate basis set representation for population transfer.
Purpose of the Study:
- To develop a new wave-packet spawning procedure for improved population transfer calculations.
- To establish a rigorous criterion for basis set expansion in quantum dynamics.
Main Methods:
- A new formulation of wave-packet spawning based on second-order perturbation theory (PT).
- Utilizes a local harmonic approximation for diabatic electronic states.
- Employs a complete basis set expression for population transfer derived from PT.
Main Results:
- The method enables detection of inadequate finite basis set expansions in variational wave packet propagation.
- Provides a rigorous criterion for basis set expansion (spawning).
- Successfully illustrated with the variational multiconfigurational Gaussian wave packet method on 1D and 2D models.
Conclusions:
- The new perturbation theory-based spawning procedure offers a robust approach for simulating interstate population transfer.
- It enhances the accuracy and reliability of quantum dynamics simulations.
- The method is extendable to various Gaussian wave packet propagation techniques and on-the-fly dynamics.
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