The relationship between molecular microscopic parameter and dielectric strength of gaseous medium can provide direction for screening the SF6 alternative gas.Based on the density functional theory,the M06-2X functional and def2 basis sets are used to calculate the electrophilic/nucleophilic reaction descriptors of 73 gas molecules,including orbital energy parameters,the parameters of conceptual density functional theory and elec-trostatic potential parameters on electron density isosurfaces.The correlation between the descriptors and the die-lectric strength is analyzed,and the dielectric strength prediction model is proposed.The lowest empty orbital energy,the positive and negative electrostatic potential surface area,the average deviation of the electrostatic po-tential and the minimum value of the condensed local electrophilic index have a strong correlation with the dielec-tric strength.The prediction model is optimal with a determination coefficient of 0.809 and a mean square error of 0.096 at 0.0002 a.u.electron density isosurface.
维普
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