用全组态相互作用量子Monte Carlo方法研究了双原子团簇与双占据组态相互作用的相关能等价性
Using full configuration interaction quantum Monte Carlo in a seniority zero space to investigate the correlation energy equivalence of pair coupled cluster doubles and doubly occupied configuration interaction
摘要：
在过去的几年里，对耦合簇双（pCCD）已显示出强相关性的描述的承诺。这一承诺与其明显的能力，以匹配结果从双占据组态相互作用（DOCI），即使后者的方法具有指数的计算成本。在这里，通过修改的全组态相互作用量子蒙特卡罗（FCIQMC）算法只采样的希尔伯特空间的资历零部门，我们表明，DOCI和pCCD的能量是一致的各种二维哈伯德模型，包括系统以及传统的配置相互作用算法无法达到。我们的计算是辅助的符号问题是大大减少了资历零空间相比，全空间。我们提出的证据，然后讨论的符号问题的波函数的系统似乎有一个简化的符号结构。
英文摘要：
Over the past few years pair coupled cluster doubles (pCCD) has shown promise for the description of strong correlation. This promise is related to its apparent ability to match results from doubly occupied configuration interaction (DOCI), even though the latter method has exponential computational cost. Here, by modifying the full configuration interaction quantum Monte Carlo (FCIQMC) algorithm to sample only the seniority zero sector of Hilbert space, we show that the DOCI and pCCD energies are in agreement for a variety of 2D Hubbard models, including for systems well out of reach for conventional configuration interaction algorithms. Our calculations are aided by the sign problem being much reduced in the seniority zero space compared with the full space. We present evidence for this, and then discuss the sign problem in terms of the wave function of the system which appears to have a simplified sign structure.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
