Auer Alexander A
Institut für Chemie, Technische Universität Chemnitz, D-09111 Chemnitz, Germany.
J Chem Phys. 2009 Jul 14;131(2):024116. doi: 10.1063/1.3167766.
Benchmark calculations of (17)O NMR chemical shifts for a series of 19 molecules with 22 chemical shifts are presented. This includes calculations at the HF-SCF, DFT (BP86 and B3-LYP), MP2, CCSD(T), and for a special case full CCSDT level of theory using basis sets of quadruple zeta quality and better. The effects of the quality of the geometry, electron correlation, basis set, and the inclusion of zero-point vibrational and temperature corrections are discussed in detail and the results are compared to gas-phase experimental values. Mean and standard deviations are 6 and 24 ppm for HF-SCF, -20 and 14 ppm for BP86, -20 and 13 ppm for B3-LYP, and 26 and 12 ppm for MP2. Results at the CCSD(T)/pz3d2f level of theory using geometries optimized at the CCSD(T)/cc-pVTZ level of theory exhibit a mean deviation of 16 ppm and a standard deviation of 6 ppm. A mean deviation of 6 ppm and a standard deviation of 4 ppm are obtained if these values are corrected for zero-point vibrational and temperature effects.
给出了一系列19个分子22个化学位移的(17)O核磁共振化学位移的基准计算。这包括在HF-SCF、DFT（BP86和B3-LYP）、MP2、CCSD(T)水平下的计算，以及在一个特殊情况下使用四重zeta及更高质量基组的全CCSDT理论水平的计算。详细讨论了几何结构质量、电子相关、基组以及零点振动和温度校正的包含对结果的影响，并将结果与气相实验值进行了比较。HF-SCF的平均值和标准偏差分别为6 ppm和24 ppm，BP86为-20 ppm和14 ppm，B3-LYP为-20 ppm和13 ppm，MP2为26 ppm和12 ppm。在使用CCSD(T)/cc-pVTZ理论水平优化的几何结构的CCSD(T)/pz3d2f理论水平下的结果显示平均偏差为16 ppm，标准偏差为6 ppm。如果对这些值进行零点振动和温度效应校正，则平均偏差为6 ppm，标准偏差为4 ppm。
