利用铅离子可以获得倍频效应增益的非线性光学材料。研究铅氧多面体及其配位环境对倍频效应增益的影响机制，有助于进一步理解非线性光学材料中微观结构与宏观光学效应之间的内在联系，为设计合成新颖非线性光学材料提供指导。本项目基于阴离子基团理论和现代极化理论，以含孤立BO3基团或者含B5O9基团的铅硼酸盐，含孤立PO4基团的铅磷酸盐等为研究对象，通过计算不同材料在外电场中的宏观极化率、原子电荷变化以及倍频效应、电荷分布、化学键特征等，着力研究铅氧多面体及其配位环境对倍频效应增益的影响机制。预期通过本项目的实施，可以初步揭示铅硼酸盐/铅磷酸盐等材料中各原子对光电场的响应及其对倍频效应的贡献，揭示阴离子基团与铅氧多面体不同的连接方式对材料倍频效应增益的影响机制。

The second harmonic generation (SHG) coefficients can be enhanced using the lead cations. It is interesting to investigate the contribution from the lead-oxygen polyhedron to the enhancement of the SHG coefficients because it can help to deeply understand the relationship between the microscopic units and the optical response, and it can also help to design and synthesize novel nonlinear optical compounds. Based on the anionic group theory and the modern theory of polarization, this project will investigate the relationship between the lead-oxygen polyhedron and the enhancement of the SHG coefficients using the macroscopic polarization, the variation of the atomic charges, the SHG coefficients, the distribution of atomic charges, and the chemical bonds of the nonlinear optical compounds containing different lead-oxygen polyhedron and anionic groups (isolated BO3 groups, complex B5O9 groups, isolated PO4 groups). After this project was finished, we can find out the optical response from the atomic charges and their contribution to the SHG response, and we can also find out the relationship between the enhancement of SHG coefficients and the bonding pattern among lead-oxygen polyhedron and the anionic groups.