The low-lying electronic states of the tungsten monosulfide (WS) molecule have been investigated using laser-induced fluorescence excitation spectra and high-level ab initio calculations. 29 vibronic bands in total are experimentally observed in the range of 13,100 – 21,500 cm⁻¹ and grouped into 8 electronic transition systems. The spectroscopic constants including the vibrational frequency, rotational constant and radiative lifetime in the low-lying excited electronic state are obtained by analysis of the rovibrational-resolved spectra. Seven lowest Ω sub-states that belong to the lowest three Λ-S states considering the spin-orbit effect, i.e. the ground state ³Σ⁻, first and second excited states ⁵Π and ³Φ, are identified through single-vibrational-level emission spectra. In addition, seven Ω = 1 excited sub-states in the visible energy range are identified, which are consecutively consistent with the ab initio calculation results of the sixth to twelfth Ω = 1 sub-states. The experimental and theoretical results on WS molecule may provide a benchmark to study the electronic structure of those molecules with strong spin-orbit coupling and electron-electron correlation.

使用激光诱导的荧光激发光谱和高水平的从头算已经研究了单硫化钨（WS）分子的低电子态。在13,100 – 21,500 cm ^-1的范围内，实验观察到总共29个振动带，并分为8个电子过渡系统。通过分析旋振解析光谱，获得了低层激发电子态的光谱常数，包括振动频率，旋转常数和辐射寿命。属于最低的三个Λ-S七个最低Ω子状态各州考虑自旋-轨道的效果，即，基态³ Σ ^- ，第一和第二激发态⁵ Π和³ Φ，通过单振动级发射光谱鉴定。另外，在可见能量范围内，确定了七个Ω= 1激发子状态，这些状态与第六到第十二Ω= 1子状态的从头计算结果连续一致。WS分子的实验和理论结果可为研究具有强自旋轨道耦合和电子-电子相关性的分子的电子结构提供基准。