Kupka Teobald
Institute of Chemistry, University of Opole, 45-052 Opole, Poland.
Magn Reson Chem. 2009 Mar;47(3):210-21. doi: 10.1002/mrc.2369.
Density functional theory (DFT) was used to estimate water's isotropic nuclear shieldings and indirect nuclear spin-spin coupling constants (SSCCs) in the Kohn-Sham (KS) complete basis set (CBS) limit. Correlation-consistent cc-pVxZ and cc-pCVxZ (x = D, T, Q, 5, and 6), and their modified versions (ccJ-pVxZ, unc-ccJ-pVxZ, and aug-cc-pVTZ-J) and polarization-consistent pc-n and pcJ-n (n = 0, 1, 2, 3, and 4) basis sets were used, and the results fitted with a simple mathematical formula. The performance of over 20 studied density functionals was assessed from comparison with the experiment. The agreement between the CBS DFT-predicted isotropic shieldings, spin-spin values, and the experimental values was good and similar for the modified correlation-consistent and polarization-consistent basis sets. The BHandH method predicted the most accurate (1)H, (17)O isotropic shieldings and (1)J(OH) coupling constant (deviations from experiment of about -0.2 and -1 ppm and 0.6 Hz, respectively). The performance of BHandH for predicting water isotropic shieldings and (1)J(OH) is similar to the more advanced methods, second-order polarization propagator approximation (SOPPA) and SOPPA(CCSD), in the basis set limit.
密度泛函理论（DFT）用于在Kohn-Sham（KS）完备基组（CBS）极限下估算水的各向同性核屏蔽和间接核自旋-自旋耦合常数（SSCCs）。使用了相关一致的cc-pVxZ和cc-pCVxZ（x = D、T、Q、5和6）及其修改版本（ccJ-pVxZ、unc-ccJ-pVxZ和aug-cc-pVTZ-J）以及极化一致的pc-n和pcJ-n（n = 0、1、2、3和4）基组，并将结果用一个简单的数学公式拟合。通过与实验比较评估了20多种研究的密度泛函的性能。对于修改后的相关一致和极化一致基组，CBS DFT预测的各向同性屏蔽、自旋-自旋值与实验值之间的一致性良好且相似。BHandH方法预测的（1）H、（17）O各向同性屏蔽和（1）J（OH）耦合常数最为准确（与实验的偏差分别约为-0.2和-1 ppm以及0.6 Hz）。在基组极限下，BHandH预测水各向同性屏蔽和（1）J（OH）的性能与更先进的方法，即二阶极化传播子近似（SOPPA）和SOPPA（CCSD）相似。
