Liquid chloroform structure from computer simulation with a full ab initio intermolecular interaction potential.

Area of Science:

• Computational chemistry
• Molecular dynamics simulations
• Physical chemistry

Background:

• Accurate molecular models are crucial for understanding liquid properties.
• Existing empirical force fields for chloroform have limitations.
• Ab initio methods offer a rigorous approach to developing molecular potentials.

Purpose of the Study:

• To develop a high-accuracy ab initio force field for chloroform.
• To validate the force field against experimental data.
• To enable reliable molecular dynamics simulations of liquid chloroform.

Main Methods:

• Calculated intermolecular interaction energies using second-order Møller-Plesset perturbation theory.
• Employed coupled cluster methods for energy calibration.
• Extrapolated to complete basis set limit values using Dunning's correlation consistent basis sets.
• Developed a 5-site force field model for molecular dynamics simulations.

Main Results:

• Achieved quantitative agreement with experimental atomwise radial distribution functions.
• Reproduced experimental diffusion coefficients across various thermodynamic conditions.
• Demonstrated that the ab initio force field rivals empirical force fields with polarization.

Conclusions:

• The developed ab initio force field provides a reliable and accurate model for liquid chloroform.
• This work represents a significant advancement in ab initio force field development.
• The model's accuracy enables precise molecular dynamics simulations for studying chloroform's behavior.