Coarse-graining strategy for molecular pair interactions: A reaction coordinate study for two- and three-dimensional...

Area of Science:

• Computational chemistry and physics
• Molecular dynamics simulations
• Statistical mechanics

Background:

• Simulating large molecular ensembles requires efficient methods for describing interactions.
• Existing reaction coordinates can be redundant and memory-intensive, especially for symmetric molecules.
• Bridging time and length scales in simulations is a persistent challenge.

Purpose of the Study:

• To develop optimal, non-redundant reaction coordinates for molecular pairs with polar, uniaxial, or spherical symmetry.
• To minimize the size and memory requirements of interaction tables for computer simulations.
• To provide a computational methodology for deriving effective pair potentials using these coordinates.

Main Methods:

• Investigating and defining optimal reaction coordinates for molecular pairs in 2D and 3D.
• Utilizing molecular symmetries to create non-redundant coordinate sets.
• Tabulating pair interactions in the derived coordinates.
• Outlining a computational recipe based on the Boltzmann inversion principle.

Main Results:

• Optimal, symmetry-adapted reaction coordinates were identified for molecular pairs.
• Tabulated pair interactions are minimal in length and memory footprint.
• The approach is suitable for simulating complex interactions in fluid and liquid crystalline phases at low densities.
• An effective pair potential derivation methodology is provided.

Conclusions:

• The developed reaction coordinates offer computational efficiency for molecular simulations.
• This method facilitates bridging time and length scales without introducing modeling errors.
• The findings are applicable to simulating colloidal systems and complex fluids.