Graduate School of System Informatics, Kobe University, Nada-ku, Kobe 657-8501, Japan.
J Chem Phys. 2019 Sep 21;151(11):114113. doi: 10.1063/1.5109820.
A general-order stochastic perturbation algorithm is obtained from the order-by-order expansion of the imaginary-time evolution of a configuration interaction wave function. A truncation of configuration space that is required for the practical treatment of the perturbative corrections, however, does not preserve size-consistency as is the case for a truncated configuration interaction. To circumvent this problem, we formulate a linked variant of stochastic perturbation theory based on the coupled-cluster ansatz. The implementation based on the linearized coupled-cluster is compared with several full configuration interaction results. We also compare the results with those obtained from deterministic coupled-cluster and many-body perturbation theories.
从组态相互作用波函数的虚时演化的逐阶展开中得到了广义序贯随机微扰算法。然而，为了处理微扰修正而需要截断组态空间，这并不像截断组态相互作用那样保持大小一致性。为了解决这个问题，我们基于耦合簇假设制定了一个链接的随机微扰理论变体。基于线性化耦合簇的实现与几个完全组态相互作用的结果进行了比较。我们还将结果与确定性耦合簇和多体微扰理论的结果进行了比较。
