NMR Quantum Chemical Computational Study of Silicate-Based Materials

9705746 Oldfield该提案的PI将使用从头算密度泛函方法和RISC工作站集群来计算硅酸盐系统中与光谱观测值和结构相关的参数表面，例如化学位移或四极耦合常数如何随着键长和键角而变化。 然后可以使用这些来推断，例如，无序相和非晶相的M-O键长和M-O-M键角的分布。 他们将集中精力研究基于Si、Al、B和P的氧化物体系（包括混合杂原子体系;例如铝硅酸盐）。 所有这些阳离子和17-O的NMR参数可以计算，并为所有这些都有一个很好的实验数据库来验证计算。 参数表面将是第一个他们的类型，并将计算在一个足够高的水平，他们将是广泛的应用范围内的一般定量适用性。

9705746 Oldfield The PIs on this proposal will use ab initio density functional methods and a cluster of RISC work stations to computer parameter surfaces relating spectroscopic observables and structure in silicate systems, for example how the chemical shift or quadrupole coupling constant of a bridging oxygen varies with bond length and bond angle. These can then be used to deduce, e.g., the distributions of M-O bond lengths and M-O-M bond angles in disordered and amorphous phases. They will focus their efforts on oxide systems based on Si, Al, B, and P (including mixed heteroatom systems; e.g. aluminosilicates). The NMR parameters can be calculated for all of these cations and for 17-O, and for all of them there is a good experimental data base to verify the calculations. The parameter surfaces will be the first of their type and will be calculated at a sufficiently high level that they will be of general quantitative applicability for a wide range of applications.