Dittmer Anneke, Stoychev Georgi L, Maganas Dimitrios, Auer Alexander A, Neese Frank
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
J Chem Theory Comput. 2020 Nov 10;16(11):6950-6967. doi: 10.1021/acs.jctc.0c00067. Epub 2020 Oct 9.
In this work, we explore the accuracy of post-Hartree-Fock (HF) methods and double-hybrid density functional theory (DFT) for the computation of solid-state NMR chemical shifts. We apply an embedded cluster approach and investigate the convergence with cluster size and embedding for a series of inorganic solids with long-range electrostatic interactions. In a systematic study, we discuss the cluster design, the embedding procedure, and basis set convergence using gauge-including atomic orbital (GIAO) NMR calculations at the DFT and MP2 levels of theory. We demonstrate that the accuracy obtained for the prediction of NMR chemical shifts, which can be achieved for molecular systems, can be carried over to solid systems. An appropriate embedded cluster approach allows one to apply methods beyond standard DFT even for systems for which long-range electrostatic effects are important. We find that an embedded cluster should include at least one sphere of explicit neighbors around the nuclei of interest, given that a sufficiently large point charge and boundary effective potential embedding is applied. Using the pcSseg-3 basis set and GIAOs for the computation of nuclear shielding constants, accuracies of 1.6 ppm for Li, 1.5 ppm for Na, and 5.1 ppm for K as well as 9.3 ppm for F, 6.5 ppm for Cl, 7.4 ppm for Br, and 7.5 ppm for Mg as well as 3.8 ppm for Zn can be achieved with MP2. Comparing various DFT functionals with HF and MP2, we report the superior quality of results for methods that include post-HF correlation like MP2 and double-hybrid DFT.
在这项工作中，我们探索了后哈特里 - 福克（HF）方法和双杂化密度泛函理论（DFT）用于计算固态核磁共振化学位移的准确性。我们应用了嵌入簇方法，并针对一系列具有长程静电相互作用的无机固体，研究了簇大小和嵌入的收敛性。在一项系统研究中，我们使用包含规范的原子轨道（GIAO）核磁共振计算，在DFT和MP2理论水平上讨论了簇设计、嵌入过程以及基组收敛性。我们证明，对于分子体系能够实现的核磁共振化学位移预测精度，可以推广到固体体系。一种合适的嵌入簇方法甚至允许人们对长程静电效应很重要的体系应用超越标准DFT的方法。我们发现，给定足够大的点电荷和边界有效势嵌入，嵌入簇应至少包括感兴趣原子核周围的一层明确的相邻原子球。使用pcSseg - 3基组和GIAO来计算核屏蔽常数，MP2方法对于Li可达到1.6 ppm的精度，对于Na为1.5 ppm，对于K为5.1 ppm，对于F为9.3 ppm，对于Cl为6.5 ppm，对于Br为7.4 ppm，对于Mg为7.5 ppm，对于Zn为3.8 ppm。将各种DFT泛函与HF和MP2进行比较，我们报告了包括MP2和双杂化DFT等包含后HF相关的方法具有更优的结果质量。
