Physics Department, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931-1295, USA.
Magn Reson Chem. 2010 Dec;48 Suppl 1:S56-60. doi: 10.1002/mrc.2620.
We present (1)H NMR chemical shift calculations of liquid water based on first principles molecular dynamics simulations under periodic boundary conditions. We focus on the impact of computational parameters on the structural and spectroscopic data, which is an important question for understanding how sensitive the computed (1)H NMR resonances are upon variation of the simulation setup. In particular, we discuss the influence of the exchange-correlation functional and the size of the basis set, the choice for the fictitious electronic mass and the use of pseudopotentials for the nuclear magnetic resonance (NMR) calculation on one hand and the underlying Car-Parrinello-type molecular dynamics simulations on the other hand. Our findings show that the direct effect of these parameters on (1)H shifts is not big, whereas the indirect dependence via the structural data is more important. The (1)H NMR chemical shifts clearly reflect the induced structural changes, illustrating once again the sensitivity of (1)H NMR observables on small changes in the local chemical structure of complex hydrogen-bonded liquids.
我们基于周期性边界条件下的第一性原理分子动力学模拟，展示了液态水的（1）H NMR 化学位移计算。我们重点研究了计算参数对结构和光谱数据的影响，这对于理解计算所得（1）H NMR 共振随模拟设置变化的敏感程度是一个重要的问题。特别是，我们讨论了交换相关泛函和基组大小、虚拟电子质量的选择以及核磁共振（NMR）计算中赝势的使用对（1）H 位移的直接影响，以及另一方面对基于 Car-Parrinello 型分子动力学模拟的间接影响。我们的研究结果表明，这些参数对（1）H 位移的直接影响不大，而通过结构数据的间接影响则更为重要。（1）H NMR 化学位移清楚地反映了诱导的结构变化，再次说明了（1）H NMR 观测值对复杂氢键液体局部化学结构微小变化的敏感性。
