A high level ab initio study on electronic states of sulfur dimer S₂ is carried out by utilizing multi-reference configuration interaction plus Davidson correction (MRCI+Q) method. The modification to the electronic structures caused by spin-orbit coupling (SOC) effect is taken into consideration by the state-interacting method with the full Breit-Pauli Hamiltonian. The potential energy curves (PECs) of 19 Λ-S states and 52 Ω states generated from the Λ-S states are calculated. With the aid of calculated SOC matrix elements and the PECs of the Ω states, we discuss the predissociaiton of the B³Σ_u⁻ state. The variation of line width of B³Σ_u⁻- X³Σ_g⁻ transitions with vibrational quantum number v' of the B³Σ_u⁻ are determined from Fermi golden rule calculations. Our study indicate that the predissociation of the B³Σ_u⁻ state is induced by the strong spin-orbit coupling with different electronic excited states, resulting in the abnormal dependence of the dissociation rate on vibrational states.

硫二聚体S _2的电子态从头开始进行了高级研究，方法是利用多参考构型相互作用加Davidson校正（MRCI + Q）方法。通过具有全Breit-Pauli哈密顿量的状态相互作用方法，考虑了自旋轨道耦合（SOC）效应引起的电子结构的变化。计算了从Λ-S状态生成的19个Λ-S状态和52Ω状态的势能曲线（PEC）。随着SOC计算矩阵元素的帮助和Ω状态的胸肌，我们讨论了B的predissociaiton ³ Σ _ü ^-状态。B的线宽度的变化³ Σ _Ü ^- - X ³ Σ_克^-与振动量子数转换v的B的' ³ Σ _Ü ^-从费米黄金规则计算来确定。我们的研究表明，B的预离解³ Σ _Ü ^-状态由强的自旋轨道耦合感应与不同的电子激发态，导致在振动状态下的解离速率的异常依赖性。