Rock climbing: A local-global algorithm to compute minimum energy and minimum free energy pathways

Area of Science:

• Computational chemistry
• Physical chemistry
• Chemical dynamics

Background:

• Calculating minimum energy paths is crucial for understanding chemical and physical processes.
• Existing methods for computing reaction coordinates present significant theoretical and computational challenges.
• A reliable method for pathway determination is needed to advance quantitative and qualitative process studies.

Purpose of the Study:

• To present a new local-global approach for calculating minimum energy or minimum free energy paths.
• To provide a method that simplifies the study of reaction coordinates.
• To overcome challenges associated with initial path guesses in global pathway finders.

Main Methods:

• A novel local-global approach based on gradual optimization of an action.
• Utilizes a local algorithm to extend the current path in small, manageable steps.
• Does not require an initial guess of the reaction path, unlike traditional global algorithms.

Main Results:

• The local-global approach successfully calculates paths between known reactants and products.
• Demonstrates the ability to find the steepest descent path, providing an exact answer.
• Validated with numerical examples on the Mueller potential and a solvated ring system's conformational transition.

Conclusions:

• The presented local-global approach offers an efficient and robust method for determining minimum energy paths.
• This technique simplifies reaction coordinate calculations and removes the need for initial path estimations.
• The approach has broad applicability in studying complex chemical and physical transformations.