Influence of external electric field on molecular microscopic descriptors of non-polar insulating gases

Molecular microscopic descriptors without external electric field are commonly used for the prediction of insulating strength in gaseous medium. However, insulating gases are subjected to external electric field in electrical equipment, and the molecular microscopic descriptors are affected. Therefore, it is necessary to investigate the influence of external electric field on molecular microscopic descriptors. The Gaussian 16 software is employed to calculate the global parameter with the M06-2X functional and the 6–311++G (d, p) basis set. The wavefunction analysis software Multiwfn is used to obtain electrostatic potential parameter. In this paper, three directions of external electric field with magnitude ranging from 0 to 0.03 a.u. have been set to 10 non-polar insulating gas molecules. According to the type of molecular point group, the effect of direction and magnitude of external electric field on the molecular microscopic descriptors has been analyzed. The results indicate that the molecular microscopic descriptors are affected by the direction and magnitude of external electric field. The change rate of microscopic descriptors increases with the increase of external electric field magnitude. And the influence of the direction of external electric field is associated with the molecular symmetry. In conclusion, the effect of direction and magnitude of external electric field is needed to be considered when analyzing the effect of external electric field on molecular microscopic descriptors.