First-Principles Parametrization of Polarizable Coarse-Grained Force Fields for Ionic Liquids

Area of Science:

• Computational chemistry
• Materials science
• Molecular dynamics

Background:

• Simulating molecular liquids requires accurate force fields.
• Explicit dipole-polarizable force fields are crucial for capturing molecular interactions.
• Coarse-graining simplifies complex systems but often sacrifices accuracy.

Purpose of the Study:

• To develop an ab initio parametrization scheme for explicitly dipole-polarizable force fields.
• To enable arbitrarily coarse-grained representations of molecular liquids.
• To create accurate polarizable coarse-grained force fields for ionic liquids.

Main Methods:

• Developed an ab initio parametrization scheme based on first-principles.
• Used a single global scaling factor for particle size, fitted to experimental mass density.
• Derived polarizable coarse-grained force fields for specific ionic liquids and anions.

Main Results:

• Successfully derived polarizable coarse-grained force fields for 1-alkyl-3-methylimidazolium cations and common anions.
• Achieved good agreement between simulation results and experimental data.
• Demonstrated the scheme's ability to handle varying alkyl-chain lengths.

Conclusions:

• The developed ab initio scheme provides accurate, polarizable coarse-grained force fields.
• These force fields are suitable for simulating molecular liquids where polarizability is significant.
• The method is applicable to systems like energy storage devices.