Accelerated sampling by infinite swapping of path integral molecular dynamics with surface hopping

Area of Science:

• Quantum mechanics
• Computational chemistry
• Statistical mechanics

Background:

• Accurate thermal equilibrium sampling is crucial for multi-level quantum systems.
• Existing methods like surface hopping and path-integral molecular dynamics have limitations in efficiency.

Purpose of the Study:

• To investigate the infinite swapping limit of a multi-level ring polymer representation.
• To develop a more efficient method for sampling thermal equilibrium in quantum systems.

Main Methods:

• Investigated the infinite swapping limit of a multi-level ring polymer representation.
• Developed a multiscale integrator for the infinite swapping limit.
• Connected surface hopping with mean-field path-integral molecular dynamics.

Main Results:

• The infinite swapping limit significantly accelerates thermal equilibrium sampling.
• The proposed multiscale integrator enables efficient sampling based on limiting dynamics.
• Numerical results show a huge improvement in sampling efficiency compared to direct simulations.

Conclusions:

• The infinite swapping limit provides a powerful approach for efficient quantum system simulations.
• This method bridges surface hopping and path-integral molecular dynamics.
• The developed integrator enhances the practical application of this technique.