This study attempted to propose an efficient scheme at the coupled cluster linear response (CCLR) level to perform large-scale excited-state calculations of not only local excitations but also nonlocal ones such as charge transfers and transitions between delocalized orbitals. Although standard applications of fragmentation techniques to the excited-state calculations brought about the limitations that could only deal with local excitations, this study solved the problem by evaluating the excited states as the poles of dynamical polarizability. Because such an approach previously succeeded at the time-dependent density functional theory level [H. Nakai and T. Yoshikawa, J. Chem. Phys. 146, 124123 (2017)], this study was considered as an extension to the CCLR level. To evaluate the dynamical polarizability at the CCLR level, we revisited three equivalent formulas, namely, coupled-perturbed self-consistent field (CPSCF), random phase approximation (RPA), and Green's function (GF). We further extended these formulas to the linear-scaling methods based on the divide-and-conquer (DC) technique. We implemented the CCLR with singles and doubles (CCSDLR) program for the six schemes, i.e., the standard and DC-type CPSCF, RPA, and GF. Illustrative applications of the present methods demonstrated the accuracy and efficiency. Although the standard three treatments could exactly reproduced the conventional frequency-domain CCSDLR results, their computational costs were commonly higher than that of the conventional ones due to large amount of computations for individual frequencies of the external electric field. The DC-type treatments, which approximately reproduced the conventional results, could achieve quasilinear scaling computational costs. Among them, DC-GF was found to exhibit the best performance.

中文翻译：

---

基于分治法的耦合簇线性响应方法评估了利用动态极化率进行的大规模激发态计算。

这项研究试图在耦合簇线性响应（CCLR）级别上提出一种有效的方案，以执行不仅局部激励而且还进行非局部激励（例如，离域轨道之间的电荷转移和跃迁）的大规模激发态计算。尽管碎片化技术在激发态计算中的标准应用带来了只能处理局部激发的局限性，但本研究通过将激发态视为动态极化率的极点来解决了这一问题。因为这种方法先前在随时间变化的密度泛函理论水平上是成功的[H。Nakai和T. Yoshikawa，J。Chem。物理 146，124123（2017）]，该研究被认为是CCLR水平的延伸。要评估CCLR级别的动态极化率，我们重新介绍了三个等效公式，即耦合摄动自洽场（CPSCF），随机相位逼近（RPA）和格林函数（GF）。我们进一步将这些公式扩展到基于分而治之（DC）技术的线性缩放方法。我们针对六个方案（即标准和DC型CPSCF，RPA和GF）实施了带有单打和双打（CCSDLR）程序的CCLR。本方法的说明性应用证明了准确性和效率。尽管标准的三种处理方法可以准确地再现常规频域CCSDLR结果，但是由于对外部电场的各个频率进行了大量的计算，因此它们的计算成本通常高于常规方法。DC型治疗 近似地再现了常规结果，可以实现准线性缩放计算成本。其中，发现DC-GF表现出最佳性能。