The dielectric constant: Reconciling simulation and experiment

Area of Science:

• Computational chemistry
• Materials science

Background:

• Classical non-polarisable models often inaccurately predict dielectric constants.
• Existing models do not fully account for electronic polarization or potential energy surface mismatches.

Purpose of the Study:

• To develop a simple correction scheme to enhance dielectric constant predictions.
• To incorporate electronic polarization and potential energy surface effects into classical models.

Main Methods:

• Developed a correction scheme using experimental refractive index for electronic polarization.
• Introduced an empirical scaling factor for point charges to address potential energy surface mismatches.
• Validated the scheme on methanol and benchmark datasets.

Main Results:

• The correction scheme significantly improved dielectric constant predictions.
• Systematic underestimation of dielectric constants by standard models was eliminated.
• The method showed remarkable improvements across four different models and diverse compounds.

Conclusions:

• The proposed correction scheme effectively enhances the accuracy of classical non-polarisable models.
• Accounting for electronic polarization and potential energy surface effects is crucial for accurate dielectric constant prediction.
• The correction term should be integrated into future model development and validation.