Tabet Jean, Taher Fadia, Adem Ziad
Faculty of Sciences II, Research Platform in Nanosciences and Nanotechnology, Laboratory of Experiments and Computation of Materials and Molecules (EC2M), Lebanese University, Campus Fanar, P.O. Box: 90656, Beirut, Lebanon.
Faculty of Engineering III, Laboratory of Molecular Quantum Mechanics and Modeling (MQMM), Lebanese University, Hadath Campus, Beirut, Lebanon.
J Mol Model. 2022 Jul 12;28(8):219. doi: 10.1007/s00894-022-05209-5.
The lowest-lying electronic states of HfS molecule have been described by using the theoretical ab initio methods, state-averaged full valence complete active space self-consistent field (SA-CASSCF) and multireference configuration interaction with single and double excitation (MRCI-SD). These calculations have predicted 22 electronic states below 40,124 cm. The unobserved states [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] have been explored for the first time. The potential energy curves (PECs) have been constructed, and the term energy values at equilibrium T, vibrational constants ω, and ωχ have been calculated for all predicted states. Also, the permanent dipole moments (PDMs) as well as the transition dipole moments (TDMs) have been examined and presented as function of the internuclear distance R. In addition, by employing the spin-orbit coupling in the calculations, 43 Ω components have been obtained below 40,645 cm. The observed states, named AΣ and BΠ, have been assigned respectively as [Formula: see text] and [Formula: see text] of [Formula: see text]. All the calculated spectroscopic constants are found in good agreement with the experiment.
通过理论从头算方法，即态平均全价完全活性空间自洽场（SA-CASSCF）和含单双激发的多参考组态相互作用（MRCI-SD），对HfS分子的最低电子态进行了描述。这些计算预测了40124厘米以下的22个电子态。首次探索了未观测到的态[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]、[公式：见正文]和[公式：见正文]。构建了势能曲线（PECs），并计算了所有预测态在平衡温度T下的项能量值、振动常数ω和ωχ。此外，还研究了永久偶极矩（PDMs）以及跃迁偶极矩（TDMs），并将其表示为核间距R的函数。另外，通过在计算中采用自旋轨道耦合，在40645厘米以下获得了43个Ω分量。观测到的态，命名为AΣ和BΠ，分别被指定为[公式：见正文]的[公式：见正文]和[公式：见正文]。所有计算得到的光谱常数与实验结果吻合良好。
