Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA.
J Chem Phys. 2013 Feb 21;138(7):074103. doi: 10.1063/1.4791560.
Simple modifications of complete basis set extrapolation formulas chosen from the literature are examined with respect to their abilities to reproduce a diverse set of 183 reference atomization energies derived primarily from very large basis set standard, frozen core coupled-cluster singles, doubles plus perturbative triples (CCSD(T)) with the aug-cc-pVnZ basis sets. This reference set was augmented with a few larger chemical systems treated with explicitly correlated CCSD(T)-F12b using a quadruple zeta quality basis set followed by extrapolation to complete basis set limit. Tuning the extrapolation formula parameters for the present reference set resulted in substantial reductions in the error metrics. In the case of the best performing approach, the aVnZ extrapolated results are equivalent to or better than results obtained from raw aV(n + 3)Z basis set calculations. To the extent this behavior holds for molecules outside the reference set, it represents an improvement of at least one basis set level over the original formulations and a further significant reduction in the amount of computer time needed to accurately approximate the basis set limit.
本文研究了文献中选择的完全基组外推公式的简单修改，以考察它们在重现主要来自非常大基组标准、冻结核耦合簇单双加微扰三的 183 个参考原子化能方面的能力，这些参考能来自 aug-cc-pVnZ 基组。该参考集通过使用四重 zeta 质量基组处理几个更大的化学体系的显式相关 CCSD(T)-F12b 进行了扩充，然后外推到完全基组极限。为当前参考集调整外推公式参数可显著降低误差指标。在表现最佳的方法的情况下，aVnZ 外推结果与原始 aV(n + 3)Z 基组计算结果相当或更好。在这种行为适用于参考集之外的分子的情况下，它代表了至少一个基组水平的改进，并且大大减少了准确逼近基组极限所需的计算机时间量。
