SeH+离子低激发态的电子结构和跃迁性质的理论研究  

Theoretical study on electronic structure and transition properties of excited states for SeH+anion

作　　者：滑亚文[1] 刘以良[1] 万明杰[2] Hua Ya-Wen;Liu Yi-Liang;Wan Ming-Jie(College of Electrical and Information Engineering,Southwest Minzu University,Chengdu 610225,China;Computational Physics Key Laboratory of Sichuan Province,Yibin University,Yibin 644007,China)

机构地区：[1]西南民族大学电气信息工程学院,成都610225 [2]宜宾学院计算物理四川省高等学校重点实验室,宜宾644007

出　　处：《物理学报》2020年第15期32-38,共7页Acta Physica Sinica

基　　金：中央高校基本科研业务费专项资金(批准号:2019NYB07)资助的课题.

摘　　要：采用内收敛多组态相互作用及Davidson修正方法精确地计算了SeH+离子能量最低的3个离解极限对应的12个L-S态的势能曲线.计算中考虑了芯-价电子关联、标量相对论修正和自旋-轨道耦合效应.结果表明在30000-40000 cm^–1处W态的曲线存在许多避免交叉,导致a2, b0+, A12, A21, A30–, A40+和c1态变为了双势阱.通过求解径向薛定谔方程得到了12个L-S态和9个Ω态的光谱常数.基于势能曲线和跃迁偶极矩,预测出了A^3Π■X^3Σ^↔和A21■X10^+跃迁的弗兰克-康登因子、辐射速率和辐射寿命.首次系统地报道了SeH+离子的光谱与跃迁性质.Potential energy curves of dipole moments for 12 electronic states correlating with the Se+(4 Su) + H(2 Sg),Se+(2 Du) + H(2 Sg) and Se+(2 Pu) + H(2 Sg) dissociation channels of SeH+ anion are calculated by the ic-MRCI +Q method. The AV5 Z-DK basis set for Se atom and H atom are chosen. Scalar relativistic effect, core-valence correction, and spin-orbit coupling effect are also taken into account. In MRCI calculations, Se(1 s2 s) orbitals are frozen, H(1 s) and Se(4 s4 p) orbitals are selected as active space, and the remaining orbitals are used for the core-valence correlation.Spectroscopic parameters of 12 L–S states and 9 low-lying W states are obtained. All L–S states we selected are bound states. The X3 S–, a1△, b1∑+, A3∏ and c1∏ states each possess a large well, but the others each have a shallow well. The a1 D, b1∑+, A3∏, c1∏ and 15 S– states cross in 30000–40000 cm–1 regions. The X3 S–, a1△ and b1 S+ come from the 4π2 electronic configuration around the equilibrium region, and three states have similar values of Re. The splitting dissociation channels are obtained at a spin-orbital coupling level. The calculated energy differences among five dissociation channels are in excellent agreement with the experimental data, and the maximal error is smaller than 0.5%. Due to the avoided crossing between the low-lying W states, the a2,b0+, A12, A21, A30–, A40+ and c1 states all have two wells. The splitting parameters ASO of the X3 S– state and the A3∏ state are predicted at the same time, i. e. ASO(X21 – X10+) = 252.4 cm–1, ASO(A21 – A12) = 858.9 cm–1,ASO(A30– – A21) = 1213.5 cm–1 and ASO(A40+ – A30–) = 199.5 cm–1. The transition dipole moments of the A3∏ ■ X3∑– and A21 ■ X10+ transitions are obtained. The oscillator strengths, Franck-Condon factors, and radiative lifetimes of these two transitions are also predicted. The radiative lifetime of A3∏ state and A21 state are 746.6 and 787.8 ns, respectively. It implies the ability of electron transit

关 键 词：多组态相互作用 自旋-轨道耦合效应 光谱常数 辐射寿命 

分 类 号：O561.4[理学—原子与分子物理]