Properties of a Si2N molecule under an external electric field

In the present work, we adopt the ccsd/6-31g(d) method to optimize the ground state structure and calculate the vibrational frequency of the Si₂N molecule. The calculated frequencies accord satisfactorily with the experimental values, which helps confirm the ground state structure of the molecule. In order to find how the external electric field affects the Si₂N molecule, we use the density functional method B3P86/6-31g(d) to optimize the ground state structure and the time-dependent density functional theory TDDFT/6-31g(d) to study the absorption spectra, the excitation energies, the oscillator strengths, and the dipole moments of the Si₂N molecule under different external electric fields. It is found that the absorption spectra, the excitation energies, the oscillator strengths, and the dipole moments of the Si₂N molecule are affected by the external electric field. One of the valuable results is that the absorption spectra of the yellow and the blue-violet light of the Si₂N molecule each have a red shift under the electric field. The luminescence mechanism in the visible light region of the Si₂N molecule is also investigated and compared with the experimental data.