Halse Meghan E, Zagdoun Alexandre, Dumez Jean-Nicolas, Emsley Lyndon
Université de Lyon, Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon1), Centre de RMN à très hauts champs, 5 rue de la Doua, 69100 Villeurbanne, France.
Université de Lyon, Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon1), Centre de RMN à très hauts champs, 5 rue de la Doua, 69100 Villeurbanne, France; Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
J Magn Reson. 2015 May;254:48-55. doi: 10.1016/j.jmr.2015.02.016. Epub 2015 Mar 7.
A method for quantitatively calculating nuclear spin diffusion constants directly from crystal structures is introduced. This approach uses the first-principles low-order correlations in Liouville space (LCL) method to simulate spin diffusion in a box, starting from atomic geometry and including both magic-angle spinning (MAS) and powder averaging. The LCL simulations are fit to the 3D diffusion equation to extract quantitative nuclear spin diffusion constants. We demonstrate this method for the case of (1)H spin diffusion in ice and L-histidine, obtaining diffusion constants that are consistent with literature values for (1)H spin diffusion in polymers and that follow the expected trends with respect to magic-angle spinning rate and the density of nuclear spins. In addition, we show that this method can be used to model (13)C spin diffusion in diamond and therefore has the potential to provide insight into applications such as the transport of polarization in non-protonated systems.
介绍了一种直接从晶体结构定量计算核自旋扩散常数的方法。该方法使用刘维尔空间中的第一性原理低阶关联（LCL）方法，从原子几何结构出发，在一个盒子中模拟自旋扩散，同时考虑魔角旋转（MAS）和粉末平均效应。将LCL模拟结果与三维扩散方程进行拟合，以提取定量的核自旋扩散常数。我们针对冰和L-组氨酸中（1）H自旋扩散的情况演示了该方法，获得的扩散常数与聚合物中（1）H自旋扩散的文献值一致，并且遵循关于魔角旋转速率和核自旋密度的预期趋势。此外，我们表明该方法可用于模拟金刚石中（13）C自旋扩散，因此有可能为非质子化体系中的极化传输等应用提供见解。
