Quantum-Classical Nonadiabatic Dynamics: Coupled- vs Independent-Trajectory Methods.

Area of Science:

• Quantum chemistry
• Theoretical chemistry
• Chemical dynamics

Background:

• Trajectory-based mixed quantum-classical methods face challenges like decoherence and inaccurate nuclear wave packet splitting.
• These issues lead to incorrect quantum population predictions and unphysical nuclear dynamics in nonadiabatic processes.

Purpose of the Study:

• To propose a new quantum-classical scheme addressing limitations of traditional methods for coupled electron-nuclear dynamics.
• To improve the accuracy of predicting quantum populations and nuclear dynamics in nonadiabatic processes.

Main Methods:

• Approximating coupled electron-nuclear equations using the exact factorization of the electron-nuclear wave function.
• Developing a quantum-classical scheme based on coupled classical trajectories.
• Comparing the scheme against full quantum mechanical wave packet dynamics for challenging model systems.

Main Results:

• The proposed scheme offers a potential solution to decoherence and spatial splitting problems.
• Demonstrates improved accuracy in modeling challenging nonadiabatic processes compared to traditional methods.

Conclusions:

• The exact factorization framework provides a robust foundation for accurate quantum-classical dynamics.
• The developed scheme offers a promising alternative for studying complex electron-nuclear interactions.