SternheimerGW: A program for calculating GW quasiparticle band structures and spectral functions without unoccupied states

The SternheimerGW software uses time-dependent density-functional perturbation theory to evaluate GW quasiparticle band structures and spectral functions for solids. Both the Green’s function G and the screened Coulomb interaction W are obtained by solving linear Sternheimer equations, thus overcoming the need for a summation over unoccupied states. The code targets the calculation of accurate spectral properties by convoluting G and W using a full frequency integration. The linear response approach allows users to evaluate the spectral function at arbitrary electron wavevectors, which is particularly useful for indirect band gap semiconductors and for simulations of angle-resolved photoelectron spectra. The software is parallelized efficiently, integrates with version 6.3 of Quantum Espresso, and is continuously monitored for stability using a test farm.SternheimerGW软件采用含时密度泛函微扰理论（time-dependent density-functional perturbation theory），用于计算固体的GW准粒子能带结构与谱函数。其格林函数（Green’s function）G与屏蔽库仑相互作用W均可通过求解线性斯特恩海默方程得到，从而免去了对未占据态的求和步骤。本代码通过全频率积分对G和W进行卷积，以实现高精度的光谱特性计算。线性响应方法支持用户在任意电子波矢下计算谱函数，这一特性对于间接带隙半导体以及角分辨光电子能谱的模拟尤为实用。该软件具备高效并行化能力，可与Quantum Espresso 6.3版本集成，并通过测试集群持续监控其运行稳定性。