Rusakov Yuriy Yu, Rusakova Irina L
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russian Federation.
Phys Chem Chem Phys. 2023 Jul 19;25(28):18728-18741. doi: 10.1039/d3cp02664g.
The basis sets that are used in the quantum chemical calculations of P NMR chemical shifts have always been one of the most important factors of accuracy. Regardless of what high-quality approach is employed, using basis sets of insufficient flexibility in the important angular regions may give poor results and lead to misassignments of the signals in the P NMR spectra. In this work, it was found that the existing nonrelativistic basis sets for phosphorus atom of double- and triple- quality, specialized for the P NMR chemical shifts calculations, are essentially undersaturated in the -angular space that occurred to play a significant role in the overall accuracy of these calculations. This problem has been thoroughly investigated, and new pecS- ( = 1, 2) basis sets for phosphorus chemical shifts calculations were proposed. The exponents and contraction coefficients for the pecS- basis sets were generated with the property-energy consistent method that has been introduced in our earlier paper, and has been proven useful in the creation of efficient property-oriented basis sets. New basis sets were optimized using the GIAO-DFT method with the B97-2 functional. Extensive benchmark calculations showed that the pecS-1 and pecS-2 basis sets provide very good accuracy, characterized by the corrected mean absolute percentage errors against the experiment of about 7.03 and 4.42 ppm, respectively. In particular, the accuracy of P NMR chemical shifts calculations achieved with the pecS-2 basis set is one of the most favorable accuracies for today. We believe that our new pecS- ( = 1, 2) basis sets for phosphorus atom will prove useful in modern large-scale quantum chemical calculations of P NMR chemical shifts.
用于磷核磁共振化学位移量子化学计算的基组一直是影响计算精度的最重要因素之一。无论采用何种高质量方法，在重要角度区域使用灵活性不足的基组可能会导致结果不佳，并导致磷核磁共振谱信号的错误归属。在这项工作中，发现现有的用于磷核磁共振化学位移计算的双精度和三精度非相对论磷原子基组，在对角空间中本质上是不饱和的，而对角空间在这些计算的整体精度中起着重要作用。对这个问题进行了深入研究，并提出了用于磷化学位移计算的新的pecS-（=1,2）基组。pecS-基组的指数和收缩系数是用我们早期论文中引入的性质-能量一致方法生成的，该方法已被证明在创建高效的面向性质的基组方面很有用。使用GIAO-DFT方法和B97-2泛函对新基组进行了优化。广泛的基准计算表明，pecS-1和pecS-2基组提供了非常好的精度，分别以相对于实验的校正平均绝对百分比误差约7.03和4.42 ppm为特征。特别是，使用pecS-2基组实现的磷核磁共振化学位移计算精度是目前最有利的精度之一。我们相信，我们新的用于磷原子的pecS-（=1,2）基组将在现代大规模磷核磁共振化学位移量子化学计算中证明是有用的。
