论文标题
通过自适应配置互动，耦合群集外部校正
Coupled Cluster Externally Corrected by Adaptive Configuration Interaction
论文作者
论文摘要
外部校正的耦合群集（CC）方法，其中提出了自适应配置相互作用（ACI）波函数提供的外部群集振幅，称为ACI-CC。通过通过群集分析利用配置相互作用和耦合群集之间的连接，使用从ACI获得的高阶T3和T4项可以从传统耦合群集中增强T1和T2振幅方程。在耦合的集群迭代期间，这些高阶贡献保持冷冻，并且对CCSD的成本不增加。我们已经在三个封闭系统上进行了基准测试：与其他校正后的耦合群集方法相比，与其他校正后的耦合簇方法相比，铍二聚体，羰基氧化物和环丁二烯的结果良好。在所有情况下，在“金标准” CCSD（t）结果上加入了这些外部校正，表明ACI-CCSD（t）可用于评估系统中的强相关效应，并作为更为复杂的外部校正的廉价起点。
An externally corrected coupled cluster (CC) method, where an adaptive configuration interaction (ACI) wave function provides the external cluster amplitudes, named ACI-CC, is presented. By exploiting the connection between configuration interaction and coupled cluster through cluster analysis, the higher-order T3 and T4 terms obtained from ACI are used to augment the T1 and T2 amplitude equations from traditional coupled cluster. These higher-order contributions are kept frozen during the coupled cluster iterations and do not contribute to an increased cost with respect to CCSD. We have benchmarked this method on three closed-shell systems: beryllium dimer, carbonyl oxide, and cyclobutadiene, with good results compared to other corrected coupled cluster methods. In all cases, the inclusion of these external corrections improved upon the "gold standard" CCSD(T) results, indicating that ACI-CCSD(T) can be used to assess strong correlation effects in a system and as an inexpensive starting point for more complex external corrections.
