While the title question is a clear “yes” from purely theoretical arguments, the case is less clear for practical calculations with finite (one-particle) basis sets. To shed further light on this issue, the convergence to the basis set limit of CCSD (coupled cluster theory with all single and double excitations) and of different approximate implementations of CCSD-F12 (explicitly correlated CCSD) has been investigated in detail for the W4-17 thermochemical benchmark. Near the CBS ([1-particle] complete basis set) limit, CCSD and CCSD(F12^*) agree to within their respective uncertainties (about ±0.04 kcal/mol) due to residual basis set incompleteness error, but a nontrivial difference remains between CCSD-F12b and CCSD(F12^*), which is roughly proportional to the degree of static correlation. The observed basis set convergence behavior results from the superposition of a rapidly converging, attractive, CCSD[F12]–CCSD-F12b difference (consisting mostly of third-order terms) and a more slowly converging, repulsive, fourth-order difference between CCSD(F12^*) and CCSD[F12]. For accurate thermochemistry, we recommend CCSD(F12^*) over CCSD-F12b if at all possible. There are some indications that the nZaPa family of basis sets exhibits somewhat smoother convergence than the correlation consistent family.

中文翻译：

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CCSD和近似CCSD-F12变体会收敛到相同的基集限制吗？雾化能量的情况

从纯粹的理论论据来看，标题问题是明确的“是”，但对于使用有限（单粒子）基集的实际计算，情况就不太清楚了。为了进一步阐明该问题，针对W4，已经详细研究了CCSD（具有所有单激励和双激励的耦合聚类理论）和CCSD-F12（显式相关CCSD）的不同近似实现的基集极限的收敛性。 -17热化学基准。在接近CBS（[1-粒子]完整基础集）的极限时，由于残留基础集不完全性误差，CCSD和CCSD（F12 ^*）在各自的不确定性内（约±0.04 kcal / mol）达成一致，但两者之间仍然存在不小的差异。 CCSD-F12b和CCSD（F12 ^*），大致与静态相关程度成正比。观察到的基集收敛行为是由快速收敛的，有吸引力的CCSD [F12] –CCSD-F12b差异（主要由三阶项组成）和CCSD之间较慢的收敛，排斥，四阶差异叠加而成的。 F12 ^*）和CCSD [F12]。为了获得准确的热化学作用，我们建议尽可能使用CCSD（F12 ^*），而不要使用CCSD-F12b。有迹象表明，nZaPa族基础集比相关一致族具有更平滑的收敛性。