Calculation of SF₆molecule structure and properties based on density functional theory
-
Abstract
: :T To investigate the regulation mechanism of external electric fields on the electronic structure and properties of SF? molecules and provide theoretical support for their applications in insulation, electric field control, and other fields, this study optimized the ground-state structure of SF? molecules using the M062X/6-311g** method based on density functional theory (DFT). The variation laws of molecular dipole moment, average static polarizability, Mulliken charge population, frontier orbital energy, energy gap, infrared spectrum, and excited-state properties were analyzed when an external electric field of -0.03~0.03 a.u. was applied along the X-axis. Additionally, the excitation energy, excitation wavelength, and oscillator strength of the first 15 excited states of SF? molecules were calculated via the hybrid CIS method. The results show that without an external electric field, SF? is a nonpolar molecule with a symmetric and stable structure. Under the action of an external electric field, the molecular symmetry decreases, the dipole moment increases, and the molecule transforms into a polar molecule, leading to a reduction in geometric structure stability. The average static polarizability significantly increases, which is conducive to improving the gas insulation performance. Mulliken charges undergo directional transfer, resulting in the reconstruction of electron cloud distribution. The energy gap of frontier orbitals decreases, enhancing chemical reactivity. The number of characteristic absorption peaks in the infrared spectrum increases, indicating richer vibration modes. The excitation energy and excitation wavelength exhibit non-monotonic changes of first increasing and then decreasing, and the oscillator strengths of excited states 7-9 are non-zero, which provides the possibility for regulating the excitation wavelength via external electric fields.
-
-
DownLoad: