论文标题
对称耦合群集理论中的功率系列近似
A Power Series Approximation in Symmetry Projected Coupled Cluster Theory
论文作者
论文摘要
预计的Hartree-fock理论提供了对许多强相关性的准确描述，但没有正确描述弱关联的系统。另一方面，诸如配置相互作用或耦合聚类理论之类的单参考方法可以处理弱相关的问题，但不能正确考虑强相关性。理想情况下，我们想将这些方法结合在对称耦合的群集方法中，但这远非直接。在这项工作中，我们提供了一种替代公式，以识别当我们结合这两个方法学链时出现的所谓分离群集操作员。我们的配方显示了模型系统和小分子的有希望的结果。
Projected Hartree-Fock theory provides an accurate description of many kinds of strong correlations but does not properly describe weakly-correlated systems. On the other hand, single-reference methods such as configuration interaction or coupled cluster theory can handle weakly-correlated problems but cannot properly account for strong correlations. Ideally, we would like to combine these approaches in a symmetry-projected coupled cluster approach, but this is far from straightforward. In this work, we provide an alternative formulation to identify the so-called disentangled cluster operators which arise when we combine these two methodological strands. Our formulation shows promising results for model systems and small molecules.
