Reducing the cost of evaluating the committor by a fitting procedure

Area of Science:

• Chemical Physics
• Computational Chemistry
• Biomolecular Dynamics

Background:

• Accurate identification of reaction coordinates is vital for elucidating reaction mechanisms in complex systems.
• Current methods often rely on calculating the committor, a computationally expensive process.
• The high cost of committor evaluation limits the applicability of reaction coordinate identification techniques.

Purpose of the Study:

• To develop a more computationally efficient method for identifying reaction coordinates.
• To reduce the cost associated with evaluating committors in complex systems.
• To enable broader application of reaction coordinate identification in chemical and biomolecular simulations.

Main Methods:

• A novel fitting procedure to estimate committor probabilities.
• Utilizing a sigmoid function to approximate committors from a limited set of numerically evaluated points.
• Employing the standard shooting procedure for initial committor evaluations along a transition path.

Main Results:

• The proposed fitting procedure reduces the computational cost of committor evaluation by one to two orders of magnitude.
• Accurate estimation of committors for configurations along a transition path.
• Successful validation on a model Brownian particle system and the alanine dipeptide isomerization.

Conclusions:

• The developed fitting procedure offers a significant computational advantage for reaction coordinate identification.
• This method enhances the feasibility of studying reaction dynamics in complex chemical and biomolecular systems.
• The approach provides a cost-effective alternative for committor evaluation in computational studies.