An automated calculation pipeline for differential pair interaction energies with molecular force fields using the...

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Materials Science

Background:

• Accurate calculation of intermolecular interactions is crucial for molecular modeling.
• Existing methods for deriving interaction energies can be complex and time-consuming.
• Bridging molecular and mesoscopic scales requires robust parameterization methods.

Purpose of the Study:

• To present an automated computational pipeline for calculating differential pair interaction energies.
• To enable the derivation of parameters for mesoscopic simulations like Dissipative Particle Dynamics (DPD).
• To provide an open, robust, and efficient computational scheme for organic molecular dimers.

Main Methods:

• Utilized the Tinker molecular modeling package for automated calculations.
• Employed molecular force fields (MM3, MMFF94, OPLS-AA, AMOEBA09) for energy calculations.
• Integrated molecular dynamics simulations for coordination numbers and DPD for repulsions.
• Validated results with Density Functional Theory (DFT) calculations.

Main Results:

• Successfully approximated global minimum energy monomers and dimers.
• Enabled configuration sampling across various monomer-monomer distances.
• Derived Flory-Huggins parameters and isotropic particle-particle repulsions for DPD.
• Demonstrated the pipeline's utility for a surfactant-water mixture.

Conclusions:

• The developed pipeline offers a novel and automated approach for calculating differential pair interaction energies.
• This method facilitates the generation of mesoscopic particles with accurate repulsive interactions.
• The study contributes an academically available, open computational scheme for molecular dimers.