基于多体微扰理论的GW方法可以精确计算材料的准粒子能量、能带结构和准粒子寿命等激发态性质。在前期工作中，我们针对周期性体材料开发了一套全自洽的GW方法。本项目致力于发展和优化该方法，并将其应用于具有基础研究意义和使用价值的热点材料体系。主要研究内容包括：研究和阐述非自洽、部分自洽、全自洽GW近似等自洽方式对准粒子能量的影响；研究导带截断、对角化近似等近似手段对准粒子能量的计算精度和效率的影响，寻找最优近似；优化傅立叶变换算法以及发展介电函数矩阵的快速计算方法，对GW程序进行系统优化，发展高效的全自洽GW近似方法和计算程序；系统研究二维材料激发态的电子结构和性质，预测其光电特性，并积极开展与实验研究的合作。本项目的顺利实施将为纳米电子学领域中材料的制备与光电器件应用提供坚实的物理基础。

The GW method based on many-body perturbation theory can accurately predict the excited properties of materials such as quasiparticle energy, band structure and liftetime of quasiparticle states. In previous work, we developed a fully self-consistent GW method for periodic material. This project is devoted to the development and optimization of this method and we will apply the GW method to the material system with significance of basic research and application purpose, including: We will study the effects of non-self-consistent, partial self-consistent and fully self-consistent GW method on the quasiparticle energy; We will also study the effects of approximations like conduction band truncation and diagonal approximation on the accuracy and efficiency of quasiparticle energy; Based on the numerical research (optimization of Fourier transform algorithm and fast calculation of dielectric function matrix), we will further optimize our algorithm to improve the efficiency of GW calculation; We will systematically investigate the excitation properties of 2D materials, predict their optelectronic properties and cooperate with experimental group. The implementation of the project will provide a solid basis for the fabrication and application of materials in the field of nanoelectronics.