Analysis of Molecular Orbital Properties of SF6 with Density Functional Theory (DFT)

Abstract

This study investigates the molecular orbital properties of SF 6 , which is still widely used in power equipment in spite of the environmental disadvantages. Employing different basis sets of Density functional theory(DFT), energy profile and harmonic vibrational frequencies of SF 6 are calculated using B3LYP/6-311+G(d,p), B3PW91/augccpvtz and CCSD/6-311+G(d,p) basis sets. Molecular ionization potential, electron affinity and electron energy gap properties that explain the dielectric behavior of insulants are evaluated using the basis sets. When the results of the calculated properties are compared with those in the literature, B3LYP/6-311+G(d,p) basis set gives more coherent results. By calculating and comparing the molecular properties at different polarization levels of this basis set, the most compatible basis set alternatives for the SF 6 molecule are determined. These results provide an insight into the DFT basis sets that can be used for mixing SF 6 with different buffer gases and examining the decomposition products.