Dielectric properties of liquid phase molecular clusters using the external field method: molecular dynamics study

Area of Science:

• Computational chemistry
• Molecular dynamics
• Dielectric spectroscopy

Background:

• Dielectric properties are crucial for understanding molecular behavior in various environments.
• Accurate computational methods are needed to predict these properties, especially for complex systems.
• The external field method with reaction field approximations is a promising technique.

Purpose of the Study:

• To evaluate the accuracy of the external field method for calculating dielectric properties.
• To assess its applicability to molecules with and without permanent dipole moments.
• To determine the limitations of the method regarding permanent dipole moment magnitude.

Main Methods:

• Utilized the external field method with reaction field approximations for molecular simulations.
• Analyzed dielectric properties, including relative static dielectric constant and Debye relaxation time.
• Compared simulation results with experimental data for various molecular liquids.

Main Results:

• The method accurately predicted relative static dielectric constants for polar and non-polar liquids, including 1,4-dioxane (zero dipole moment).
• Debye relaxation time constants were accurately estimated for molecules with permanent dipole moments under 12 Debye.
• The external field method demonstrated good agreement with literature experimental values.

Conclusions:

• The external field method is a reliable computational tool for determining dielectric properties of molecular liquids.
• Its accuracy is validated for molecules with zero and non-zero permanent dipole moments.
• The method's accuracy for relaxation time constants is established for dipole moments below 12 D.