Accessible Molecular System Creator: Building Molecular Configurations Based on the Inaccessible Molecular Volume and...

Area of Science:

• Computational chemistry and physics
• Statistical mechanics
• Molecular modeling

Background:

• Monte Carlo (MC) stochastic sampling is crucial for molecular simulations, linking macroscopic properties to atomistic interactions via statistical mechanics.
• Dynamic MC simulations, using Markovian chains, are prevalent, but static MC approaches, like Rosenbluth sampling, offer an alternative.
• Static MC has faced challenges, particularly in mapping accessible molecular volumes for stepwise system building.

Purpose of the Study:

• To address the primary obstacle hindering the adoption of static, Rosenbluth-like MC sampling in atomistic simulations.
• To demonstrate a novel method for analytically mapping molecular accessible and inaccessible volumes.
• To enhance the capability of static building processes for molecular configurations.

Main Methods:

• Re-examination of static Monte Carlo (MC) sampling theory.
• Development of an analytical method to map molecular accessible and inaccessible volumes based on excluded volume interactions.
• Application of the method to Rosenbluth-like static building of atomistic configurations.

Main Results:

• A breakthrough in analytically mapping molecular accessible volumes for static MC sampling.
• Substantially enhanced ability to create molecular samples using a Rosenbluth-like static building process.
• Demonstration of a method applicable to generating initial configurations for MC and molecular dynamics simulations.

Conclusions:

• The developed approach overcomes a major hurdle in static MC simulations, facilitating wider application of Rosenbluth-based methods.
• This advance enables more efficient construction of molecular ensembles through static building.
• The method serves as a foundation for free energy perturbation calculations by accurately estimating chemical work.