论文标题
在周期性条件下的Koopmans光谱功能
Koopmans spectral functionals in periodic-boundary conditions
论文作者
论文摘要
Koopmans光谱功能旨在同时描述原子，分子，纳米结构和周期性晶体的基态特性和带电的激发。这是通过通过简单但具有物理动机的轨道密度依赖性校正来增强标准密度功能来实现的。这些校正作用于一组局部轨道，在周期系统中，这些轨道类似于最大局部的Wannier功能。与原始的直接超级电池实现相差[Phys。 Rev. X 8，021051（2018）]，我们在这里讨论i）使用显式布里鲁因区域采样的周期性代码所需的复杂但有效的形式主义，以及II）计算具有密度功能扰动理论的筛选的Koopmans校正。除了提供系统尺寸的改进缩放外，目前的开发还可以直接用Koopmans功能来计算频带结构。介绍和讨论了开源量子意式浓缩咖啡分布以及对原型绝缘和半导体系统的应用。
Koopmans spectral functionals aim to describe simultaneously ground state properties and charged excitations of atoms, molecules, nanostructures and periodic crystals. This is achieved by augmenting standard density functionals with simple but physically motivated orbital-density-dependent corrections. These corrections act on a set of localized orbitals that, in periodic systems, resemble maximally localized Wannier functions. At variance with the original, direct supercell implementation [Phys. Rev. X 8, 021051 (2018)], we discuss here i) the complex but efficient formalism required for a periodic-boundary code using explicit Brillouin zone sampling, and ii) the calculation of the screened Koopmans corrections with density-functional perturbation theory. In addition to delivering improved scaling with system size, the present development makes the calculation of band structures with Koopmans functionals straightforward. The implementation in the open-source Quantum ESPRESSO distribution and the application to prototypical insulating and semiconducting systems are presented and discussed.
