Systematic procedure to parametrize force fields for molecular fluids

Area of Science:

• Computational chemistry
• Molecular modeling
• Physical chemistry

Background:

• Developing accurate force fields for molecular fluids is crucial for molecular simulations.
• Existing methods can be computationally expensive and time-consuming.
• Parameterization strategies often rely on limited experimental data.

Purpose of the Study:

• To present a new, systematic strategy for developing molecular fluid force fields.
• To improve the efficiency and accuracy of force field parameterization.
• To validate the method across various molecules and simulation levels.

Main Methods:

• Intermolecular parameters fitted to experimental properties (critical temperature, dielectric constant, surface tension, liquid density).
• Lennard-Jones parameters (εii, σii) optimized for surface tension and liquid density.
• Partial charges determined by matching the dielectric constant.
• Application to diverse molecules (e.g., pyridine, methanol, EMIM-BF4) at various conditions.

Main Results:

• The proposed method systematically yields accurate force field parameters.
• Using surface tension as a target property is more effective than heat of vaporization.
• The strategy allows parameter determination with a reduced number of simulations.
• Calculated properties include heat of vaporization, radial distribution functions, and self-diffusion coefficients.

Conclusions:

• The developed strategy offers an efficient and accurate approach to force field generation for molecular fluids.
• This method provides a reliable framework for molecular simulations across different scales.
• The findings highlight the importance of surface tension in force field parameterization.