ZnH分子激发态的电子结构和跃迁性质的理论计算

Theoretical study on the electronic structure and transition properties of excited state of ZnH molecule

采用高精度的多参考组态相互作用方法计算了ZnH分子的能量最低四个离解限Zn(~1Sg)+H(~2Sg),Zn(~3P2u)+H(Sg),Zn^+(~2Sg)+H^-(~1Sg)和Zn(~1Pu)+H(~2Sg)对应的7个Λ-S态的势能曲线.计算中考虑了Davidson修正、标量相对论效应、自旋-轨道耦合效应和芯-价电子关联.基于计算的Λ-S和?态的势能曲线,数值求解一维径向Schr?dinger方程得到了束缚电子态的光谱常数,理论计算结果与之前的实验结果符合较好.计算得到了7个Λ-S态的电偶极矩随核间距的变化曲线,分析了电子组态成分变化对电偶极矩和成键性质的影响.计算结果表明,C^2Σ^+态是一个离子对态.进一步地,分析了避免交叉点附近?态的Λ-S态组成的变化规律,讨论了避免交叉现象对跃迁偶极矩的影响.基于计算的跃迁偶极矩、Franck-Condon因子和振动能级信息,给出了束缚激发态(2)1/2,(3)1/2,(4)1/2和(1)3/2的v′=0—2振动能级的自发发射寿命,结果与现有实验值相符合.

The potential energy curves（PECs） associated with the lowest four dissociation limits,i.e.,Zn（^1Sg） ＋ H（^2Sg）,Zn（^3Pu）＋H（^2Sg）,Zn^＋（^2S-2g）^＋H^-（^1Sg） and Zn（^1Pu）＋H（Sg）,are calculated by using a high-level configuration interaction method.The Davidson correction,scalar relativistic effect and spin-orbit coupling effect are taken into account in calculation.On the basis of our calculated PECs of Λ-S and ？ states,the spectroscopic constants including Te,ωe,ωeχ e,B e and R e are evaluated by numerical solution of one-dimensional Schr？dinger equation.The computed spectroscopic constants are reasonably consistent with previous experimental results.The dipole moment curves of the 7 Λ-S states are presented,and the influences of the variation of electronic configuration on the dipole moment and bonding property are discussed.The computational results reveal the ionic character of the C^2Σ^＋state.The variation of Λ-S component for？ state near the avoided crossing point is illuminated,which is used to explain the change of transition dipole moment（TDM） around the avoided crossing point.Based on the TDMs,Franck-Condon factors and the transition energies,the radiative lifetimes of v′= 0–2 vibrational levels of（2）1/2,（3）1/2,（4）1/2 and（1）3/2 states are predicted,which accord well with the available experimental values.