Targeting excited states in all-trans polyenes with electron-pair states
Targeting excited states in all-trans polyenes with electron-pair states
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DOI：
10.1063/1.4972053
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发表时间：
2016-12-21
影响因子：
4.4
通讯作者：
Boguslawski, Katharina
中科院分区：
文献类型：
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作者：
Boguslawski, Katharina
限制在电子对态的波函数是强关联系统的有前途的模型。具体来说，对耦合簇双（pCCD）的ananterior使我们能够准确地描述键的解离过程和重元素含有多个准简并单粒子态的化合物。在这里，我们扩展的pCCD方法模型激发态的运动方程（EOM）的形式主义。由于pCCD的团簇算符仅限于电子对激发，EOM-pCCD允许我们仅针对激发的电子对态。为了模拟EOM-pCCD中的单激发态，我们修改了EOM-pCCD的组态相互作用模型，使其也包含单激发态。我们提出的模型代表了一个简单的和具有成本效益的替代传统的EOM-CC方法来研究单激发电子态。激发态模型的性能进行评估对最低的激发态的铀酰阳离子和两个最低的激发态的全反式多烯。我们的数值结果表明，EOM-pCCD包括单激发是一个很好的起点，以目标单激发态。出版社：AIP Publishing
Wavefunctions restricted to electron pair states are promising models for strongly correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and heavy-element containing compounds with multiple quasi-degenerate single-particle states. Here, we extend the pCCD method to model excited states using the equation of motion (EOM) formalism. As the cluster operator of pCCD is restricted to electron-pair excitations, EOM-pCCD allows us to target excited electron-pair states only. To model singly excited states within EOM-pCCD, we modify the configuration interaction ansatz of EOM-pCCD to contain also single excitations. Our proposed model represents a simple and cost-effective alternative to conventional EOM-CC methods to study singly excited electronic states. The performance of the excited state models is assessed against the lowest-lying excited states of the uranyl cation and the two lowestlying excited states of all-trans polyenes. Our numerical results suggest that EOM-pCCD including single excitations is a good starting point to target singly excited states. Published by AIP Publishing.