Dispersion Energy in the Coupled Pair Approximation with Noniterative Inclusion of Single and Triple Excitations
Dispersion Energy in the Coupled Pair Approximation with Noniterative Inclusion of Single and Triple Excitations
复制标题
非迭代包含单次和三次激发的耦合对近似中的色散能
DOI：
10.1063/1.470646
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发表时间：
1995
影响因子：
4.4
通讯作者：
B. Jeziorski
中科院分区：
文献类型：
--
作者：
H. Williams;K. Szalewicz;R. Moszynski;B. Jeziorski
导出了耦合对（耦合簇双）近似下的二阶色散能。耦合对振幅随后被用于微扰理论类型的表达式中，以解释单激励和三激励的影响。这种方法选择性地将单体内相关图的重要类别相加到无限阶，从而与有限阶微扰处理相比，对色散相互作用进行了更好的理论描述。在不同的几何构型和基组下，对He 2、Ar-H2、Ar-HF、（HF）2、（H2O）2和He-F−进行了数值计算，以说明非微扰与微扰处理对单体内相关对色散相互作用能量的贡献的性能。
The second‐order dispersion energy in the coupled‐pair (coupled‐cluster doubles) approximation has been derived. The coupled‐pair amplitudes are subsequently used in a perturbation theory type expression to account for the effects of single and triple excitations. This approach selectively sums to infinite order important classes of intramonomer correlation diagrams resulting in a better theoretical description of the dispersion interaction compared to a finite‐order perturbation treatment. Numerical results have been obtained for He2, Ar–H2, Ar–HF, (HF)2, (H2O)2, and He–F− in various geometries and basis sets to illustrate the performance of the nonperturbative versus perturbative treatments of the intramonomer correlation contributions to the energy of the dispersion interaction.