College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007, China.
J Chem Phys. 2013 Jul 28;139(4):044306. doi: 10.1063/1.4813794.
The potential energy curves (PECs) of 50 Ω states generated from the 18 Λ-S states are studied for the first time using the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with the Davidson modification. All the 18 Λ-S states correlate to the first dissociation limit, C((3)Pg) + S((3)Pg), of CS molecule, of which only the 2(5)Π is repulsive and the A(1)Π, A(') (1)Σ(+), and 2(3)Σ(+) possess double wells. The spin-orbit (SO) coupling is accounted for by the state interaction approach with the Breit-Pauli Hamiltonian. Core-valence correlation correction is taken into account with an all-electron cc-pCV5Z basis set. Scalar relativistic correction calculations are made by the third-order Douglas-Kroll Hamiltonian approximation at the level of a cc-pVTZ basis set. All the PECs are extrapolated to the complete basis set limit. The a(') (3)Σ(+), e(3)Σ(-), 1(5)Σ(+), 1(5)Π, and d(3)Δ are found to be the inverted Λ-S states with the SO coupling included. The spectroscopic parameters of 17 Λ-S and 41 Ω bound states are evaluated. The comparisons between the present results and available measurements are performed, and excellent agreement has been found. It shows that the spectroscopic results reported here can be expected to be reliable predicted ones.
首次使用完全活性空间自洽场方法研究了由 18 Λ-S 态产生的 50 Ω 态的势能曲线（PECs），随后使用带有 Davidson 修正的内收缩多参考组态相互作用方法进行了研究。所有 18 Λ-S 态都与 CS 分子的第一离解极限 C((3)Pg) + S((3)Pg)相关联，其中只有 2(5)Π 是排斥的，A(1)Π、A(') (1)Σ(+)和 2(3)Σ(+)具有双势阱。自旋轨道（SO）耦合通过带有 Breit-Pauli 哈密顿量的状态相互作用方法来考虑。核心价电子相关校正通过全电子 cc-pCV5Z 基组来考虑。标量相对论修正计算是在 cc-pVTZ 基组的水平上通过三阶 Douglas-Kroll 哈密顿近似进行的。所有 PEC 都被外推到完全基组极限。发现 a(') (3)Σ(+)、e(3)Σ(-)、1(5)Σ(+)、1(5)Π和 d(3)Δ是包含 SO 耦合的倒置 Λ-S 态。评估了 17 Λ-S 和 41 Ω 束缚态的光谱参数。将本研究的结果与现有测量值进行了比较，发现了很好的一致性。这表明，这里报告的光谱结果可以预期是可靠的预测结果。
