Generalized coarse-grained model based on point multipole and Gay-Berne potentials.

Area of Science:

• Computational chemistry
• Molecular modeling
• Soft matter physics

Background:

• All-atom molecular mechanics simulations are computationally expensive.
• Developing efficient coarse-grained models is crucial for simulating larger systems.
• Accurate representation of electrostatic interactions is vital for molecular liquids.

Purpose of the Study:

• To develop a general coarse-grained molecular mechanics model.
• To incorporate electric point multipole expansion and the Gay-Berne potential.
• To enhance computational efficiency while maintaining accuracy for molecular simulations.

Main Methods:

• Coarse-graining van der Waals interactions using soft uniaxial ellipsoids and a generalized anisotropic Gay-Berne function.
• Representing charge distribution with point multipole expansion (charge, dipole, quadrupole) at the center of mass.
• Combining Gay-Berne and point multipole potentials in a local reference frame.
• Performing rigid-body molecular dynamics simulations.

Main Results:

• Achieved computational efficiency improvement of several orders of magnitude.
• Obtained reasonable agreement with all-atom models and experimental data for molecular liquids (benzene, methanol).
• Demonstrated the model's potential for polar molecules and biopolymers.

Conclusions:

• The developed coarse-grained model offers a significant speedup for molecular dynamics simulations.
• The model provides a good balance between computational efficiency and accuracy.
• It shows promise for simulating complex molecular systems, including those with hydrogen bonding and high charges.