Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
J Chem Phys. 2013 May 21;138(19):194103. doi: 10.1063/1.4804164.
The recently developed method [M. Musiał, J. Chem. Phys. 136, 134111 (2012)] to study double electron attached states has been applied to the description of the ground and excited state potential energy curves of the alkali metal dimers. The method is based on the multireference coupled cluster scheme formulated within the Fock space formalism for the (2,0) sector. Due to the use of the efficient intermediate Hamiltonian formulation, the approach is free from the intruder states problem. The description of the neutral alkali metal dimers is accomplished via attaching two electrons to the corresponding doubly ionized system. This way is particularly advantageous when a closed shell molecule dissociates into open shell subunits while its doubly positive cation generates the closed shell fragments. In the current work, we generate the potential energy curves for the ground and multiple excited states of the Li2 and Na2 molecules. In all cases the potential energy curves are smooth for the entire range of interatomic distances (from the equilibrium point to the dissociation limit). Based on the calculated potential energy curves, we are able to compute spectroscopic parameters of the systems studied.
最近开发的方法[M. Musiał, J. Chem. Phys. 136, 134111 (2012)]用于研究双电子附加态已应用于碱金属二聚体的基态和激发态势能曲线的描述。该方法基于 Fock 空间形式主义中为 (2,0) 扇区制定的多参考耦合簇方案。由于使用了有效的中间哈密顿形式，该方法不受侵入态问题的影响。通过将两个电子附加到相应的双离子化系统来描述中性碱金属二聚体。当一个满壳分子分解成开壳子单元，而其双正离子生成闭壳碎片时，这种方法特别有利。在当前的工作中，我们生成了 Li2 和 Na2 分子的基态和多个激发态的势能曲线。在所有情况下，势能曲线在整个原子间距离范围内（从平衡点到离解极限）都是平滑的。基于计算出的势能曲线，我们能够计算所研究系统的光谱参数。
