外电场下NH分子的特性研究

Study on the Properties of NH Molecule under External Electric Field

以6-311G(3df,3pd)为基组,采用B3LYP方法研究了NH分子在不同外电场(0^-0.03 a.u.)下的基态参数、总能量、偶极矩、HOMO能级、LUMO能级和能隙,在优化构型的基础上,使用相同的基组和同等强度的外电场,采用CIS-DFT方法研究了NH分子前9个激发态的激发能、激发波长和振子强度。结果表明:NH分子的几何参数随电场强度变化明显。电场由0变化至-0.03 a.u.时,体系的总能量不断增加,偶极矩不断减小;HOMO能级和LUMO能级受外电场的影响明显,两者的能隙随外电场的增加不断增大。激发态的激发能、跃迁波长电场变化明显,而外电场并没有改变电子的跃迁特性。

Using 6-311 G(3 DF,3 pd)as the base set,B3 LYP method was used to study the effect of external electric field(0^-0.03)on NH molecule a.Based on the optimized configuration,the excitation energies,excitation wavelengths and oscillator strengths of the first nine excited states of NH molecule were studied by CIS-DFT method.The results show that the geometric parameters of NH molecule change obviously with the electric field strength.When the electric field changes from 0 to-0.03 a.u.,the total energy of the system increases and the dipole moment decreases;the HOMO and LUMO energy levels are obviously affected by the external electric field,and the energy gap between them increases with the increase of the external electric field.The excitation energy and transition wavelength of the excited state change obviously,but the external electric field does not change the transition characteristics of the electron.