Easy transition path sampling methods: flexible-length aimless shooting and permutation shooting.

Area of Science:

• Computational chemistry
• Statistical mechanics
• Materials science

Background:

• Transition path sampling (TPS) is crucial for studying rare events in molecular dynamics.
• Accurate and efficient sampling of transition pathways remains a computational challenge.
• Identifying reaction coordinates is key to understanding and predicting molecular processes.

Purpose of the Study:

• To develop novel, more efficient algorithms for transition path sampling.
• To improve the accuracy of reaction coordinate identification in molecular systems.
• To reduce computational costs associated with simulating rare events.

Main Methods:

• Introduced new algorithms for transition path sampling (TPS).
• Developed flexible-length trajectory versions of aimless shooting and permutation shooting.
• Applied flexible-length permutation shooting and inertial likelihood maximization for reaction coordinate optimization.

Main Results:

• Permutation shooting rigorously conserves energy and momentum.
• Flexible-length TPS methods offer simpler acceptance criteria and enhanced computational efficiency.
• Optimized reaction coordinate for vacancy migration in a 2D crystal significantly reduced trajectory recrossing.

Conclusions:

• The new flexible-length TPS algorithms provide a more efficient and accurate approach to studying rare events.
• Optimized reaction coordinates derived from these methods enhance the reliability of molecular dynamics simulations.
• These advancements facilitate the investigation of complex processes like vacancy migration in materials.