Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Building 3, Moscow 121205, Russia.
Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
J Chem Phys. 2019 Feb 14;150(6):064314. doi: 10.1063/1.5071457.
The complexes of the Ba atom and Ba cation with the rare gas atoms Ar, Kr, and Xe in the states associated with the 6s → 5d, 6p excitations are investigated by means of the multireference configuration interaction techniques. Scalar relativistic potentials are obtained by the complete basis limit extrapolation through the sequence of aug-cc-pwCVnZ basis sets with the cardinal numbers n = Q, T, 5, combined with the suitable effective core potentials and benchmarked against the coupled cluster with singles, doubles, and non-iterative triples calculations and the literature data available for selected electronic states. Spin-orbit coupling is taken into account by means of the state-interacting multireference configuration interaction calculations performed for the Breit-Pauli spin-orbit Hamiltonian. The results show weak spin-orbit coupling between the states belonging to distinct atomic multiplets. General trends in the interaction strength and long-range anisotropy along the rare gas series are discussed. Vibronic spectra of the Ba and Ba complexes in the vicinity of the S → P° and S → P° atomic transitions and diffusion cross sections of the Ba(S, D) atom in high-temperature rare gases are calculated. Comparison with available experimental data shows that multireference calculations tend to underestimate the interaction strength for excited complexes.
通过多参考组态相互作用技术研究了 Ba 原子与 Ba 阳离子与稀有气体原子 Ar、Kr 和 Xe 在与 6s→5d、6p 激发态相关的状态下的复合物。通过使用带有基数 n = Q、T、5 的 aug-cc-pwCVnZ 基组序列进行完全基极限外推，获得了标量相对论势，同时结合适当的有效核势，并与耦合簇计算进行基准测试，其中包括单电子、双电子和非迭代三电子计算以及为选定电子态提供的文献数据。通过对 Breit-Pauli 自旋轨道哈密顿量进行的态相互作用多参考组态相互作用计算来考虑自旋轨道耦合。结果表明，属于不同原子多重态的态之间的自旋轨道耦合很弱。讨论了沿稀有气体系列的相互作用强度和远程各向异性的一般趋势。计算了 Ba 和 Ba 复合物在 S→P°和 S→P°原子跃迁附近的振电子光谱以及高温稀有气体中 Ba（S，D）原子的扩散截面。与可用的实验数据的比较表明，多参考计算往往低估了激发态复合物的相互作用强度。
