Reproducing Quantum Probability Distributions at the Speed of Classical Dynamics: A New Approach for Developing Force-Field Functors

TL;DR

This paper introduces an efficient method using the Wigner-Kirkwood expansion to compute force-field functors, enabling quantum-like accuracy in molecular dynamics simulations with classical computational speed.

Contribution

The authors develop a novel approach to calculate force-field functors efficiently, matching RPMD accuracy while significantly reducing computational costs.

Findings

Achieved quantum accuracy in thermodynamic properties of Neon

Reduced computational time compared to RPMD

Potential to improve MD simulations of water and proteins

Abstract

Modeling nuclear quantum effects is required for accurate molecular dynamics (MD) simulations of molecules. The community has paid special attention to water and other biomolecules that show hydrogen bonding. Standard methods of modeling nuclear quantum effects like Ring Polymer Molecular Dynamics (RPMD) are computationally costlier than running classical trajectories. A force-field functor (FFF) is an alternative method that computes an effective force field which replicates quantum properties of the original force field. In this work, we propose an efficient method of computing FFF using the Wigner-Kirkwood expansion. As a test case, we calculate a range of thermodynamic properties of Neon, obtaining the same level of accuracy as RPMD, but with the shorter runtime of classical simulations. By modifying existing MD programs, the proposed method could be used in the future to increase the efficiency and accuracy of MD simulations involving water and proteins.