碘代乙烷分子光解离的自旋轨道从头计算理论研究

采用从头计算的二阶多组态准简并微扰理论和二阶自旋轨道多组态准简并微扰理论计算了碘代乙烷C2H5I分子与基态 原子和激发态 原子解离极限相关联的势能曲线。C2H5I分子的势能曲线表明除了 （ ）态外几个低激发态都为排斥态, 电子态在RC-I=0.346nm处有337cm-1的一个浅势阱。 （ ）和 (21A’, 11A’’)电子态的垂直激发能计算表明C2H5I分子的A带吸收谱的波长区间为33478cm-1 - 44150cm-1（226nm -299nm）,这与实验给出的(243nm-285nm)波长区间吻合较好。     

AlCl分子低激发态光谱性质的从头计算研究

AlCl 分子在天体物理、化学领域以及激光冷却方面发挥着重要作用。 本文使用高精度多参考组态相互作用方法(MRCI+Q)对 AlCl 分子低激发态进行研究。 基于获得的势能曲线(PECs)拟合电子态的光谱常数,与实验值吻合较好。 计算了电子态的偶极矩(DMs)以及自旋轨道(SO)矩阵元随核间距变化的曲线。 同时还计算了 AlCl 分子的跃迁性质,包括跃迁偶极距(TDMs)和 Franck-Condon 因子(FCFs)以及辐射寿命。 AlCl 分子的 1¹Π-1¹Σ⁺跃迁 FCFs 高度对角化,有作为激光冷却光循环的潜力。计算结果对 AlCl 分子电子结构性质后续的实验研究具有一定的参考价值。     

Configuration interaction studies on the spectroscopic properties of PbO including spin-orbit coupling

Lead oxide(Pb O), which plays the key roles in a range of research fields, has received a great deal of attention. Owing to the large density of electronic states and heavy atom Pb including in Pb O, the excited states of the molecule have not been well studied. In this work, high level multireference configuration interaction calculations on the low-lying states of Pb O have been carried out by utilizing the relativistic effective core potential. The effects of the core-valence correlation correction, the Davidson modification, and the spin–orbital coupling on the electronic structure of the Pb O molecule are estimated. The potential energy curves of 18 Λ-S states correlated to the lowest dissociation limit(Pb(~3P_g) + O(~3P_g)) are reported. The calculated spectroscopic parameters of the electronic states below 30000 cm~(-1), for instance, X~1Σ~+, 1~3Σ~+,and 1~3Σ~-, and their spin–orbit coupling interaction, are compared with the experimental results, and good agreements are derived. The dipole moments of the 18 Λ-S states are computed with the configuration interaction method, and the calculated dipole moments of X~1Σ~+and 1~3Σ~+are consistent with the previous experimental results. The transition dipole moments from 1~1Π, 2~1Π, and 2~Σ to X~1Σ~+and other singlet excited states are estimated. The radiative lifetime of several low-lying vibrational levels of 1~1Π, 2~1Π, and 2~1Σ~+ states are evaluated.