I_(2)^(+)离子低能电子态的计算和光谱研究  

Computational and spectroscopic investigation of two lowest electronic states of I_(2)^(+)

作　　者：王泽育 崔琪 和小虎[1] 卢丹华 邱选兵[1] 何秋生 赖云忠[1] 李传亮[1] WANG Zeyu;CUI Qi;HE Xiaohu;LU Danhua;QIU Xuanbing;HE Qiusheng;LAI Yunzhong;LI Chuanliang(School of Applied Sciences,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学应用科学学院,山西太原030024

出　　处：《量子电子学报》2022年第4期477-484,共8页Chinese Journal of Quantum Electronics

基　　金：国家自然科学基金(u1810129,11904252);应用光学国家重点实验室开放基金(SKLAO-201902);山西科技厅青年科技研究基金(201904D131025);山西省高等学校科技创新计划(2019L0634)。

摘　　要：采用高精度从头算方法对I_(2)^(+)离子最小的四个Ω子态(X^(2)Π_(3/2,g),X^(2)Π_(1/2,g),A^(2)Π_(3/2,u)和A^(2)Π_(1/2,u))进行了研究,并与实验获得的高分辨率吸收光谱进行了比较。首先利用多参考组态相互作用(MRCI)方法计算了四个Ω电子态的势能曲线,求解了一维径向薛定谔方程,并推导出各电子态的振动-转动能级。随后利用拟合获得的相应光谱参数和计算得到的跃迁偶极矩矩阵元,计算了A^(2)Π_(3/2,u)-X^(2)Π_(3/2,g)系统的υ′=11−19和υ″=1−5的45个带的跃迁强度,并计算了A^(2)Π_(3/2,u)态的υ′=11−19振动能级的辐射寿命。最后,计算给出了I_(2)^(+)的A^(2)Π_(1/2,u)Ω子态的较高振动能级的预解离寿命,并讨论了其预离解机理。Four lowestΩsubstates(X^(2)Π_(3/2,g),X^(2)Π_(1/2,g),A^(2)Π_(3/2,u) and A^(2)Π_(1/2,u))of the I_(2)^(+) cation are studied by high-precision ab initio calculations,and the calculated results are compared with the experimental high-resolution spectra of literatures.Firstly,the potential energy curves of the fourΩsubstates are calculated using the multi-reference configuration interaction(MRCI)method,and the rovibrational levels of these electronic states are derived by solving the radial Schrodinger rovibrational equation.Then,¨molecular constants are obtained by fitting energy levels to a spectroscopic model,and based on the fitted spectroscopic constants and calculated transition dipole moment matrix elements,line strengths of vibronic bands in the A^(2)Π_(3/2,u)-X^(2)Π_(3/2,g) system for 45 bands withυ′=11−19 andυ″=1−5 have been derived,and the Einstein A coefficients are employed to compute radiative lifetimes of theυ′=11−19 vibrational levels of the A^(2)Π_(3/2,u) state.Finally,based on the calculated predissociation lifetimes of the higher vibrational levels,the predissociation mechanism of the A^(2)Π_(1/2,u) state is discussed.

关 键 词：光谱学 势能曲线 爱因斯坦A系数 谱线强度 预解离 

分 类 号：O561.3[理学—原子与分子物理]