Enhanced path sampling using subtrajectory Monte Carlo moves.

Area of Science:

• Computational Chemistry
• Statistical Mechanics
• Molecular Dynamics

Background:

• Path sampling methods, including Monte Carlo (MC) exploration in path space, are crucial for studying rare events like chemical reactions and protein folding.
• These methods sample short molecular dynamics (MD) trajectories, with efficiency heavily reliant on the chosen MC moves.
• The traditional shooting move has been central, but newer subtrajectory moves like stone-skipping (SS) and web-throwing offer improved efficiency.

Purpose of the Study:

• To address implementation challenges of subtrajectory moves in path sampling, particularly their one-step crossing requirement.
• To introduce a more versatile and broadly applicable subtrajectory move for enhanced path sampling.
• To demonstrate the utility of the new move across diverse systems and computational levels.

Main Methods:

• Development and introduction of the wire fencing (WF) move, a novel subtrajectory move for path sampling.
• Implementation of WF for studying a double-well Langevin model.
• Application of WF to a thin film breaking transition using classical force fields and a ruthenium redox reaction at the ab initio level.

Main Results:

• The wire fencing (WF) move is presented as a generic and versatile solution for path sampling.
• WF overcomes limitations of previous subtrajectory moves, facilitating integration with external MD programs.
• The method proves effective even when order parameter calculation is computationally expensive or not purely geometric.

Conclusions:

• The wire fencing (WF) move offers a practical and versatile advancement in path sampling techniques.
• It enhances the applicability of subtrajectory moves, especially in complex scenarios involving external codes or intricate order parameters.
• WF provides a robust strategy for studying rare events across various chemical and physical systems.