Olive Laura N, Dornshuld Eric Van, Webster Charles Edwin
Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762-9573, USA.
J Chem Phys. 2021 Sep 21;155(11):114304. doi: 10.1063/5.0057327.
This work addresses the pathological behavior of the energetics of dimethyl sulfoxide and related sulfur-containing compounds by providing the computational benchmark energetics of RE species, where R = H/CH and E = O/S, with bent and pyramidal geometries using state-of-the-art methodologies. These 22 geometries were fully characterized with coupled-cluster with single, double, and perturbative triple excitations [CCSD(T)], second-order Møller-Plesset perturbation theory (MP2), and 22 density functional theory (DFT) methods with 8, 12, and 12, respectively, correlation consistent basis sets of double-, triple-, or quadruple-ζ quality. The relative energetics were determined at the MP2 and CCSD(T) complete basis set (CBS) limits using 17 basis sets up to sextuple-ζ and include augmented, tight-d, and core-valence correlation consistent basis sets. The relative energies of oxygen-/sulfur-containing compounds exhibit exceptionally slow convergence to the CBS limit with canonical methods as well as significant basis set dependence. CCSD(T) with quadruple-ζ basis sets can give qualitatively incorrect relative energies. Explicitly correlated MP2-F12 and CCSD(T)-F12 methods dramatically accelerate the convergence of the relative energies to the CBS limit for these problematic compounds. The F12 methods with a triple-ζ quality basis set give relative energies that deviate no more than 0.41 kcal mol from the benchmark CBS limit. The correlation consistent Composite Approach (ccCA), ccCA-TM (TM for transition metals), and G3B3 deviated by no more than 2 kcal mol from the benchmark CBS limits. Relative energies for oxygen-/sulfur-containing systems fully characterized with DFT are quite unreliable even with triple-ζ quality basis sets, and 13 out of 45 combinations fortuitously give a relative energy that is within 1 kcal mol on average from the benchmark CCSD(T) CBS limit for these systems.
本研究通过使用最先进的方法提供了RE物种（其中R = H/CH且E = O/S）具有弯曲和金字塔形几何结构的计算基准能量学，从而研究了二甲基亚砜及相关含硫化合物能量学的病理行为。这22种几何结构通过耦合簇单、双和微扰三重激发[CCSD(T)]、二阶Møller-Plesset微扰理论(MP2)以及22种密度泛函理论(DFT)方法进行了全面表征，分别使用了8种、12种和12种双ζ、三ζ或四ζ质量的相关一致基组。使用17种直至六重ζ的基组，在MP2和CCSD(T)完整基组(CBS)极限下确定了相对能量学，其中包括增强型、紧密d型和芯价相关一致基组。含氧化合物/含硫化合物的相对能量学在使用标准方法时向CBS极限的收敛异常缓慢，并且对基组有显著依赖性。使用四ζ基组的CCSD(T)可能会给出定性错误的相对能量。显式相关的MP2-F12和CCSD(T)-F12方法显著加速了这些有问题化合物的相对能量向CBS极限的收敛。具有三ζ质量基组的F12方法给出的相对能量与基准CBS极限的偏差不超过0.41 kcal/mol。相关一致复合方法(ccCA)、ccCA-TM（用于过渡金属的TM）和G3B3与基准CBS极限的偏差不超过2 kcal/mol。即使使用三ζ质量基组，通过DFT全面表征的含氧化合物/含硫系统的相对能量也相当不可靠，并且45种组合中有13种偶然给出的相对能量平均与这些系统的基准CCSD(T) CBS极限相差在1 kcal/mol以内。
