A Comparative Study for Molecular Dynamics Simulations of Liquid Benzene

Area of Science:

• Computational Chemistry
• Physical Chemistry
• Materials Science

Background:

• Aromatic π-π interactions are crucial in various chemical and biological systems.
• Accurate molecular force fields are essential for simulating these interactions.
• Liquid benzene serves as a model system for studying aromatic interactions.

Purpose of the Study:

• To evaluate the performance of multiple molecular force fields in simulating liquid benzene.
• To identify the most accurate force field for describing aromatic π-π interactions.
• To understand discrepancies in force field predictions for liquid benzene.

Main Methods:

• Classical equilibrium and nonequilibrium molecular dynamics simulations were employed.
• A comprehensive set of widely used force fields were tested, including OPT-FF, AMBER 03, GAFF, OPLS-AA, OPLS-CS, CHARMM27, GROMOS 53A5, and GROMOS 53A6.
• Simulated structural and thermodynamic properties were compared against experimental data.

Main Results:

• The OPLS-AA force field demonstrated superior accuracy in reproducing both local structure and thermodynamic properties of liquid benzene.
• Other tested force fields exhibited significant failures in predicting key properties.
• Discrepancies were analyzed based on the pairwise interaction construction of the force fields.

Conclusions:

• OPLS-AA is recommended as the most reliable force field for simulating liquid benzene and similar aromatic systems.
• The study highlights the limitations of current force fields in accurately capturing π-π interactions.
• Further development of force fields is needed for improved microstructure and thermodynamic property predictions.