University of Opole, Faculty of Chemistry, 45-052 Opole, Poland.
Magn Reson Chem. 2013 Aug;51(8):482-9. doi: 10.1002/mrc.3974. Epub 2013 Jun 10.
A linear correlation between isotropic nuclear magnetic shielding constants for seven model molecules (CH2 O, H2 O, HF, F2 , HCN, SiH4 and H2 S) calculated with 37 methods (34 density functionals, RHF, MP2 and CCSD(T)), with affordable pcS-2 basis set and corresponding complete basis set results, estimated from calculations with the family of polarization-consistent pcS-n basis sets is reported. This dependence was also supported by inspection of profiles of deviation between CBS estimated nuclear shieldings and shieldings obtained with the significantly smaller basis sets pcS-2 and aug-cc-pVTZ-J for the selected set of 37 calculation methods. It was possible to formulate a practical approach of estimating the values of isotropic nuclear magnetic shielding constants at the CCSD(T)/CBS and MP2/CBS levels from affordable CCSD(T)/pcS-2, MP2/pcS-2 and DFT/CBS calculations with pcS-n basis sets. The proposed method leads to a fairly accurate estimation of nuclear magnetic shieldings and considerable saving of computational efforts.
报道了用 37 种方法（34 种密度泛函、RHF、MP2 和 CCSD(T)），用可负担的 pcS-2 基组和相应的完全基组结果，对 7 个模型分子（CH2 O、H2 O、HF、F2 、HCN、SiH4 和 H2 S）的各向同性核磁共振屏蔽常数进行计算，与极化一致的 pcS-n 基组族的计算结果进行拟合得到的线性相关。通过检查所选的 37 种计算方法的 pcS-2 和 aug-cc-pVTZ-J 基组的核屏蔽值与 CBS 估计核屏蔽值之间的偏差分布，也支持了这种相关性。可以从可负担的 CCSD(T)/pcS-2、MP2/pcS-2 和 DFT/CBS 计算中用 pcS-n 基组构建一个实用的方法，从这些计算中估算 CCSD(T)/CBS 和 MP2/CBS 水平的各向同性核磁共振屏蔽常数的值。所提出的方法对核磁共振屏蔽值的估计相当准确，并且大大节省了计算工作量。
