摘要:
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(3Pu)+H(2Sg),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,C2Σ+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.
Abstract:
The potential energy curves (PECs) associated with the lowest four dissociation limits, i.e., Zn(1Sg)+H(2Sg), Zn(3Pu)+H(2Sg), Zn+(2Sg)+H?(1Sg) and Zn(1Pu)+H(2Sg), 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 ofΛ-S and ? states, the spectroscopic constants including T e ,ωe ,ωeχe , 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 7Λ-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 C2Σ+ 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.