AsH^(+)离子的电子结构和跃迁性质  

Electronic structures and transition properties of AsH+cation

作　　者：侯秋宇 关皓益 黄雨露 陈世林 杨明 万明杰[1] Hou Qiu-Yu;Guan Hao-Yi;Huang Yu-Lu;Chen Shi-Lin;Yang Ming;Wan Ming-Jie(Faculty of Science,Yibin University,Yibin 644007,China)

机构地区：[1]宜宾学院理学部,宜宾644007

出　　处：《物理学报》2022年第21期103-109,共7页Acta Physica Sinica

基　　金：宜宾学院预研项目(批准号:2019YY06)、宜宾学院计算物理四川省高等学校重点实验室开放基金(批准号:YBXYJSWL-ZD-2020-001)和宜宾学院培育项目(批准号:2021PY71)资助的课题。

摘　　要：采用多参考组态相互作用方法计算了AsH^(+)离子前3个离解极限所对应的8个电子态(X^(2)Π,a^(4)Σ^(-),a^(2)Σ^(-),b^(4)Π,B^(2)Δ,C^(2)Σ^(+),D^(2)Π,2^(2)Σ^(+))的电子结构.As原子选择了aug-cc-pwCV5Z-PP相对论赝势基组.在计算中考虑了Davidson修正,芯-价电子关联和自旋-轨道耦合效应.拟合得到了所有态的光谱常数,离解能越大的电子态,其谐振频率越大,平衡核间距越小.考虑自旋-轨道耦合效应后,由于避免交叉,B^(2)Δ和B^(2)Δ变为双势阱结构.最后预测了a^(2)Σ^(-)→X^(2)Π,a^(4)Σ^(-)→X^(2)Π和a^(2)Σ^(-)→X^(2)Π跃迁的弗兰克-康登因子、自发辐射速率和自发辐射寿命,计算结果表明a^(4)Σ^(-)←X^(2)Π阻禁跃迁的强度很小.本文的计算结果为以后AsH^(+)离子的光谱实验研究提供理论基础.Potential energy curves(PECs),dipole moments(DMs)and transition dipole moments(TDMs)of the X^(2)Π,a^(4)Σ^(-),A^(2)Σ^(-),b^(4)Π,B^(2)Δ,C^(2)Σ^(+),D^(2)Π,2^(2)Σ^(+)states correlating with the three lowest dissociation channels of AsH+cation are calculated by using the multireference configuration interaction(MRCI)method.The Davidson correction,core-valence(CV)correlation,and spin-orbit coupling(SOC)effect are all considered.The aug-ccpV5Z all-electron basis set of H atom and the aug-cc-pwCV5Z-PP pseudopotential basis set of As atom are both selected in the calculation.In the complete active space self-consistent field(CASSCF)calculation,H(1s)and As(4 s4 p)shell are selected as active orbitals,As(3p3d)shells are selected as closed orbitals,which keeps doubly occupation,the remaining electrons are in the frozen orbitals.In the MRCI calculation,As(3p3d)shells are used for CV correlation,and the calculation accuracy can be improved.The SOC effects are considered with Breit-Pauli operators.All calculated states are bound states.The X^(2)Πis the ground state,which is a deep potential well,the dissociation energy is 3.100 eV.The b^(4)Π,C^(2)Σ^(+)and D^(2)Πare weakly bound states.The spectroscopic parameters are obtained by solving radial Schrodinger equation.To the best of our knowledge,there has been no study of the spectroscopy of AsH+cation so far.Comparing with V-hydride cations MH+(M=N,P,As),the orders of the energy levels of the low-lying states for three ions are identical.The dissociation energy and harmonic frequency both decrease with the increase of the atomic weight of M.At spin-free level,the PEC of b^(4)Πstate and the PEC of B^(2)Δ_(3/2)state cross at about 1.70A.When SOC effects are taken into account,according to the rule of avoid-crossing,the B^(2)Δ_(3/2)state and B^(2)Δ_(3/2)state change to the double potential wells,and the avoided crossing between the B^(2)Δ_(3/2)(B^(2)Δ_(3/2))state and b^(4)Π(b^(4)Π)state is observed.The transition dipole moment(TDM)of the A^(2)Σ^(-)→X^(2)Π,a^(

关 键 词：自旋-轨道耦合效应 光谱常数 弗兰克-康登因子 自发辐射寿命 

分 类 号：O469[理学—凝聚态物理]