外电场下NO_(2)分子的基态和激发态特性  

Ground State and Excited State Properties of NO_(2)Molecule with External Electric Fields

作　　者：荆涛[1] 梁冬梅[1] JING Tao;LIANG Dong-mei(Kaili University,Kaili,Guizhou,556011,China)

机构地区：[1]凯里学院,贵州凯里556011

出　　处：《凯里学院学报》2023年第3期1-7,共7页Journal of Kaili University

基　　金：凯里学院博士专项课题(BS201601)。

摘　　要：以6-311++G(d,p)为基组,采用B3LYP方法研究了NO_(2)分子在Z轴方向的外电场(0~0.04 a.u.)下的基态参数、总能量、电偶极矩、电荷分布和能级分布,并采用CIS方法研究了NO_(2)分子前9个激发态的激发能、激发波长、振子强度和紫外—可见光谱.结果表明:NO_(2)的基态参数随电场变化明显.当Z轴电场由0增加到0.04 a.u.时,键长和键角不断增大,电偶极矩先减少后增大,总能量先增大后减小,在电场F=0.01 a.u.时,总能量数值最大,电偶极矩数值最小,能隙不断减少,但Beta轨道的能隙比Alpha轨道的能隙减少更快;激发态的激发能和激发波长随电场变化明显,振子强度受电场的影响不大.紫外—可见光谱在外电场作用下,吸收峰不但发生了明显的移动,而且有分裂现象发生.A density functional method(B3LYP)with 6-311++G(d,p)basis sets has been used to study the equilibrium geometric parameters,total energies,dipole moments,charge distribution and en⁃ergy level distribution of NO_(2)molecule with external electric fields(0~0.04 a.u.)along Z-axis direc⁃tion.The excitation energy,wavelength,oscillator strength and UV-Vis absorption spectrum of NO_(2)molecule with external electric field were studied by CIS method.The results show that the geometric parameters of molecules change obviously with the external electric field.When the external electric field along Z-axis direction changes from0 to 0.04 a.u.,the bond length and bond angle constantly in⁃crease,the dipole moment(total energy)almost decreases(increases)first and then increases(de⁃creases)symmetrically,when the electric field F=0.01 a.u.,the total energy reaches the maxi-mum and the dipole moment reaches the minimum value,and the energy gap decreases continuously,but the energy gap of Beta orbit decreases faster than that of Alpha orbit.The excitation energy and wavelength of the excited state change obviously with the electric field,and the oscillator strength is not obviously affected by the electric field.With the action of external electric field,the absorption peak of UV-Vis spectrum shifts and splits obviously.

关 键 词：外电场 激发态 光谱 

分 类 号：O561[理学—原子与分子物理]