Initial sampling in symmetrical quasiclassical dynamics based on Li-Miller mapping Hamiltonian

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Chemical Dynamics

Background:

• Nonadiabatic dynamics are crucial in many chemical processes.
• Accurate simulation of these dynamics is computationally challenging.
• Symmetrical quasiclassical (SQC) methods offer a potential route for such simulations.

Purpose of the Study:

• To evaluate the performance of the symmetrical quasiclassical Li-Miller (SQC-LM) mapping Hamiltonian approach for nonadiabatic dynamics.
• To investigate the impact of different initial sampling procedures on SQC-LM dynamics.
• To compare SQC-LM results with accurate quantum dynamics calculations.

Main Methods:

• Employed the symmetrical quasiclassical Li-Miller (SQC-LM) mapping Hamiltonian.
• Tested various initial sampling approaches within the SQC-LM framework.
• Validated results against multiconfigurational time-dependent Hartree (MCTDH) quantum dynamics.

Main Results:

• The SQC-LM method provides a generally reasonable description of population dynamics for both site-exciton and linear vibronic coupling models.
• A noticeable influence of the initial sampling method on the final dynamics was observed.
• Results showed good agreement with accurate MCTDH calculations, validating the SQC-LM approach's potential.

Conclusions:

• The choice of initial sampling method is critical and system-dependent for SQC-LM dynamics.
• Combining SQC-LM with appropriate sampling strategies presents a promising avenue for studying nonadiabatic processes.
• Further research is needed to optimize sampling techniques for specific chemical systems.