Parametrization and Validation of Coarse Grained Force-Fields Derived from ab Initio Calculations

Area of Science:

• Computational materials science
• Soft matter physics
• Molecular modeling

Background:

• Accurate simulation of complex materials like liquid crystals and polymers is computationally demanding.
• Existing atomistic potentials often face limitations due to high computational cost for large systems.

Purpose of the Study:

• To develop and validate a novel, computationally efficient multisite interaction potential for simulating complex materials.
• To parameterize this potential using ab initio data obtained through the Fragmentation-Reconstruction Method (FRM).

Main Methods:

• A hybrid intermolecular potential combining anisotropic Gay-Berne sites and isotropic Lennard-Jones sites was constructed.
• Monte Carlo simulations at constant temperature and pressure were performed on p-n-phenyls and 5CB molecules.
• The potential was parameterized using ab initio data from the Fragmentation-Reconstruction Method (FRM).

Main Results:

• The proposed model successfully mimicked the rigid rings and flexible chains of the studied molecules.
• Simulations accurately reproduced phase behavior, thermodynamic, and structural properties compared to experimental data.
• The model demonstrated good agreement with experimental measures despite its simplified nature.

Conclusions:

• The developed hybrid potential offers a computationally efficient alternative for simulating large, complex molecular systems.
• This approach is suitable for materials like liquid crystals and polymers where atomistic accuracy is often prohibitive.
• The Fragmentation-Reconstruction Method (FRM) provides a reliable source for ab initio parameterization.