Communication: nonadiabatic ring-polymer molecular dynamics.

Area of Science:

• Quantum Chemistry
• Molecular Dynamics
• Computational Physics

Background:

• Calculating thermal correlation functions in electronically nonadiabatic systems is computationally challenging.
• Existing methods often struggle to accurately represent the coupled electronic and nuclear dynamics.

Purpose of the Study:

• To develop a new computational method for simulating thermal correlation functions in nonadiabatic systems.
• To improve the accuracy and scalability of molecular dynamics simulations for complex chemical processes.

Main Methods:

• An extension of ring-polymer molecular dynamics (RPMD) is proposed.
• A continuous-variable representation of electronic states within the mapping approach is employed.
• Electronic and nuclear degrees of freedom are treated on an equal footing.

Main Results:

• The method shows good agreement with exact quantum results for short to moderate time dynamics.
• It demonstrates systematic improvement over the classical implementation of the mapping approach (single-bead limit).
• The trajectory-based approach exhibits favorable scaling with the number of degrees of freedom.

Conclusions:

• The proposed RPMD extension offers a promising approach for simulating nonadiabatic dynamics.
• The method is applicable to complex molecular systems, advancing computational chemistry.
• It provides a more accurate and efficient alternative to classical approximations.