Non-adiabatic dynamics around a conical intersection with surface-hopping coupled coherent states

Area of Science:

• Quantum Chemistry
• Chemical Physics
• Computational Chemistry

Background:

• Simulating non-adiabatic dynamics is crucial for understanding chemical reactions.
• Classical trajectory methods often fail to capture quantum effects like nuclear wavepacket interference.
• Accurate modeling requires methods that account for both electronic transitions and nuclear quantum behavior.

Purpose of the Study:

• To develop a surface-hopping extension of the coupled coherent states (CCS) method.
• To incorporate quantum nuclear effects into non-adiabatic dynamics simulations.
• To accurately model interference effects and non-adiabatic transitions.

Main Methods:

• A surface-hopping extension of the coupled coherent states (CCS) method is proposed.
• The time-dependent Schrödinger equation is solved using a moving basis set guided by classical trajectories.
• Non-adiabatic transitions are modeled using a modified Tully's fewest switches algorithm.
• Trajectories are composed of phase-space Gaussians (coherent states) with electronic wave function amplitudes.

Main Results:

• The method successfully simulates non-adiabatic dynamics with quantum nuclear effects.
• It captures interference effects, which are absent in classical trajectory simulations.
• The approach provides a compact description of both interference and non-adiabatic transitions.
• Tests on a 2D conical intersection model demonstrate the method's capability.

Conclusions:

• The developed surface-hopping CCS method offers a powerful tool for simulating complex chemical dynamics.
• It accurately accounts for quantum nuclear effects and interference phenomena.
• This method advances the simulation of non-adiabatic processes, particularly around conical intersections.