A Coupled-Trajectory Strategy for Decoherence, Frustrated Hops and Internal Consistency in Surface Hopping.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Quantum Dynamics

Background:

• Surface-hopping methodologies are crucial for simulating non-adiabatic molecular dynamics.
• Existing methods often rely on an independent-trajectory picture, which can lead to issues with decoherence and internal consistency.
• Accurate modeling of photodynamics requires robust simulation schemes that account for quantum effects.

Purpose of the Study:

• To develop a more robust and reliable surface-hopping scheme.
• To address limitations of independent-trajectory approaches in simulating non-adiabatic processes.
• To improve the modeling of electronic and vibrational time-dependent properties in molecular photodynamics.

Main Methods:

• Developed a novel surface-hopping scheme based on the exact factorization and coupled trajectories.
• Treated the swarm of trajectories mimicking nuclear dynamics as a unique entity.
• Imposed energy conservation for the entire swarm and allowed energy sharing during hops.

Main Results:

• Demonstrated that a coupled-trajectory approach overcomes decoherence and internal consistency issues.
• Achieved encouraging results for electronic and vibrational time-dependent properties.
• Successfully modeled the photodynamics of fulvene and 4-(dimethylamino)benzonitrile using full-dimensional linear vibronic coupling Hamiltonians.

Conclusions:

• The proposed surface-hopping scheme offers a robust and reliable alternative to independent-trajectory methods.
• Treating trajectories as a coupled entity is key to improving simulations of non-adiabatic dynamics.
• The method shows promise for accurate predictions of molecular photodynamics.