The impact of complete basis set extrapolation schemes (CBS), diffuse functions, and tight weighted-core functions on enthalpies of formation predicted via the DLPNO-CCSD(T1) reduced Feller-Peterson-Dixon approach has been examined for neutral H,C,O-compounds. All tested three-point (TZ/QZ/5Z) extrapolation schemes result in mean unsigned deviation (MUD) below 2 kJ mol⁻¹ relative to the experiment. The two-point QZ/5Z and TZ/QZ CBS $1/l_{\max }^3$ extrapolation schemes are inferior to their inverse power counterpart ($1/\text{◂◽˙▸}{\left(l_{\max }+1/2\right)}^4$) by 1.3 and 4.3 kJ mol⁻¹. The CBS extrapolated frozen core atomization energies are insensitive (within 1 kJ mol⁻¹) to augmentation of the basis set with tight weighted core functions. The core-valence correlation effects converge already at triple-ζ, although double-ζ/triple-ζ CBS extrapolation performs better and is recommended. The effect of diffuse function augmentation converges slowly, and cannot be reproduced with double- ζ or triple- ζ calculations as these are plagued with basis set superposition and incompleteness errors.

中文翻译：

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完全基组近似、紧加权核和扩散函数对中性 H、C、O 化合物的 DLPNO-CCSD(T1) 雾化能的影响

已针对中性 H、C、 O-化合物。所有测试的三点 (TZ/QZ/5Z) 外推方案导致平均无符号偏差 (MUD) 低于 2 kJ mol ^-1相对于实验。两点式 QZ/5Z 和 TZ/QZ CBS$\mathrm{1个}/{升}_{\mathrm{最大限度}}^{\mathrm{3个}}$外推方案不如它们的逆幂对应物（$\mathrm{1个}/\text{◂◽˙▸}{\left({升}_{\mathrm{最大限度}}+\mathrm{1个}/\mathrm{2个}\right)}^{\mathrm{4个}}$) 减少 1.3 和 4.3 kJ mol ^-1。CBS 外推的冻结核原子化能量对具有紧加权核函数的基组的增加不敏感（在 1 kJ mol ^{-1以内）。}核心价相关效应已经收敛于三重 ζ，尽管双 ζ/三重 ζ CBS 外推法表现更好并被推荐。扩散函数增强的效果收敛缓慢，并且不能用双 ζ 或三重 ζ 计算重现，因为这些计算受到基组叠加和不完整性错误的困扰。