Prediction of gaseous medium insulation strength based on electrostatic potential on real space function isosurface

Area of Science:

• Computational Chemistry
• Materials Science
• Environmental Science

Background:

• Sulfur hexafluoride (SF₆) is a potent greenhouse gas used in electrical equipment, facing international restrictions.
• Developing alternative gases requires extensive and time-consuming electrical breakdown testing.
• A predictive model is crucial for efficient identification of SF₆ substitutes.

Purpose of the Study:

• To establish a structure-activity relationship model for predicting gas insulation strength.
• To identify key molecular properties correlating with insulation capabilities.
• To develop an efficient method for selecting SF₆ replacement gases.

Main Methods:

• Calculated isosurface electrostatic potential for 68 gas molecules using electron probability density, Laplacian of electron density, electron localization function, and localized orbital function.
• Analyzed distribution characteristics of these real space functions.
• Employed GAUSSIAN 16 software with M06-2X method and 6-311G++(d, p) basis set for calculations, and Multiwfn for analysis.

Main Results:

• Established correlations between electrostatic potential parameters and gas insulation strength.
• Developed a prediction model for insulation strength of gaseous mediums.
• The model using localized orbital locator function potential (threshold 0.05 a.u.) achieved R² of 0.860 and MSE of 0.0663.

Conclusions:

• A structure-activity relationship model based on electrostatic potential effectively predicts gas insulation strength.
• This approach offers a resource-efficient alternative to traditional electrical breakdown testing for identifying SF₆ substitutes.
• The developed model facilitates the search for environmentally friendlier gases for electrical applications.