Efficient and Deterministic Propagation of Mixed Quantum-Classical Liouville Dynamics

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Molecular Modeling

Background:

• Simulating systems with both quantum and classical behaviors is computationally challenging.
• Existing methods like surface-hopping solutions for the quantum-classical Liouville equation (QCLE) can be computationally expensive.
• Accurate and efficient methods are needed to study complex molecular dynamics.

Purpose of the Study:

• To propose a highly efficient mixed quantum-classical molecular dynamics scheme.
• To demonstrate the accuracy and efficiency of the proposed method.
• To provide a novel computational tool for studying mixed quantum-classical systems.

Main Methods:

• Developed a scheme based on solving the quantum-classical Liouville equation (QCLE).
• Transformed quantum-classical equations of motion into coupled first-order differential equations for c-numbers.
• Propagated the composite system using independent classical-like trajectories.

Main Results:

• The method demonstrated excellent agreement with numerically exact results for the spin-boson, photoinduced electron transfer, and Fenna-Matthews-Olsen complex models.
• Achieved high accuracy over long simulation times.
• Required several orders of magnitude fewer trajectories compared to surface-hopping QCLE solutions.

Conclusions:

• The proposed mixed quantum-classical molecular dynamics scheme is highly accurate and efficient.
• This method offers a significant advantage in computational cost compared to traditional approaches.
• The scheme is a promising tool for investigating the dynamics of complex mixed quantum-classical systems.