LoFEx - A local framework for calculating excitation energies: Illustrations using RI-CC2 linear response theory
LoFEx - A local framework for calculating excitation energies: Illustrations using RI-CC2 linear response theory
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DOI：
10.1063/1.4953360
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发表时间：
2016-06-14
影响因子：
4.4
通讯作者：
Kristensen, Kasper
中科院分区：
文献类型：
--
作者：
Baudin, Pablo;Kristensen, Kasper
我们提出了一个用于计算大分子耦合簇激发能（LoFEx）的局部框架。该方法通过自然跃迁轨道 (NTO) 的概念，利用有关感兴趣跃迁的时间相关 Hartree-Fock 信息。 NTO 与局域占据轨道和虚拟 Hartree-Fock 轨道结合使用，生成特定于每个跃迁的缩减激发轨道空间 (XOS)，在其中执行标准耦合簇计算。每个 XOS 都经过优化，以确保激发能量达到预定义的精度。我们将 LoFEx 与 RI-CC2 模型结合应用来计算一组中等大小有机分子的最低激发能。结果证明了 LoFEx 方法的黑盒性质，并表明可以在不影响 CC2 激励能量准确性的情况下节省大量计算量。由 AIP 出版社出版。
We present a local framework for the calculation of coupled cluster excitation energies of large molecules (LoFEx). The method utilizes time-dependent Hartree-Fock information about the transitions of interest through the concept of natural transition orbitals (NTOs). The NTOs are used in combination with localized occupied and virtual Hartree-Fock orbitals to generate a reduced excitation orbital space (XOS) specific to each transition where a standard coupled cluster calculation is carried out. Each XOS is optimized to ensure that the excitation energies are determined to a predefined precision. We apply LoFEx in combination with the RI-CC2 model to calculate the lowest excitation energies of a set of medium-sized organic molecules. The results demonstrate the black-box nature of the LoFEx approach and show that significant computational savings can be gained without affecting the accuracy of CC2 excitation energies. Published by AIP Publishing.