构建了系列典型的磷硅酸盐团簇结构模型, 应用量子化学从头计算方法研究了磷硅酸盐的精细结构, 选用Restricted Hartree-Fock(RHF)方法以及6-31G(d) 基组优化空间几何构型, 并计算了其拉曼光谱, 同时引入硅氧四面体应力指数(SIT)分析和讨论了磷氧四面体对硅氧四面体微环境的影响。 研究表明, 磷硅酸盐高频区硅氧四面体非桥氧的对称伸缩振动频率不仅与非桥氧所处的硅氧四面体本身的种类有关, 同时也与其邻接四面体种类及成环状况有关; 磷氧四面体具有较强的键角调节和应力传导能力, 使得硅氧四面体的振动频率相对键角不敏感; 硅氧四面体非桥氧的对称伸缩振动频率随硅氧四面体应力指数(SIT)的增加而增加, 并呈线性关系。

Quantum chemistry ab initio calculation was applied to study the hyperfine structure of ternary alkali phosphosilicates. Restricted Hartree-Fock method (RHF) with the basis sets of 6-31G(d) was employed to optimize geometric structure and calculate Raman spectra of a series of phosphosilicates model cluster structural units. Stress index of tetrahedron (SIT) was introduced to describe and classify the microstructure of ternary alkali phosphosilicates in order to investigate the effect of phosphorus-oxygen tetrahedron on the micro-environment of silicon-oxygen tetrahedron. It was suggested that the calculated vibrational wavenumbers of symmetric stretching vibration of non-bridging oxygen (NBO) depend not only on the species of the silicon-oxygen tetrahedron, which was called primary structure units, but also on the linkage of the neighboring tetrahedron and ring types. The phosphorus-oxygen tetrahedron exhibits regulative ability of bond angle and conductive ability of stress, so that the vibrational wavenumbers of silicon-oxygen tetrahedron are insensitive to the bond angle. It demonstrated that vibrational wavenumbers of NBO stretching vibration in the high frequency range show linear relationship with the value of SIT.