论文标题
使用投影仪增强波的核心孔激发和伯特 - 氨基盐方程
Core-hole excitations using the projector augmented-wave method and the Bethe-Salpeter equation
论文作者
论文摘要
我们介绍了在投影仪增强波方法框架内的核心传导频段对的贝特 - 盐方程（BSE）的实现。为了进行验证，该方法应用于钻石，石墨，六角硼氮化物以及四个锂锂液化液（LIF，LICL，Lii，Lii，Libr）的$ K $ -EDGE。我们将结果与实验，以前的理论BSE结果和基于密度的基于理论的超级核心孔法进行了比较。在所有被考虑的情况下，与实验的一致性都非常好，特别是对于峰的位置以及精细的结构。将BSE与SuperCell核心孔光谱进行比较，我们发现后者通常会定性地再现实验光谱，但是，它有时缺乏重要的细节。这是针对六角硼氮化物中钻石和氮的$ K $ edges的，我们能够在核心孔方法中缺少的BSE实验特征中解决。此外，我们表明，在某些系统中，如果将激发的电子添加到背景电荷中，那么SuperCell Core-Hole方法的性能更好。我们将这种改善的性能归因于减少的自我交流。
We present an implementation of the Bethe-Salpeter equation (BSE) for core-conduction band pairs within the framework of the projector augmented-wave method. For validation, the method is applied to the $K$-edges of diamond, graphite, hexagonal boron-nitride, as well as four lithium-halides (LiF, LiCl, LiI, LiBr). We compare our results with experiment, previous theoretical BSE results, and the density functional theory-based supercell core-hole method. In all considered cases, the agreement with experiment is excellent, in particular for the position of the peaks as well as the fine structure. Comparing BSE to supercell core-hole spectra we find that the latter often qualitatively reproduces the experimental spectrum, however, it sometimes lacks important details. This is shown for the $K$-edges of diamond and nitrogen in hexagonal boron-nitride, where we are capable to resolve within the BSE experimental features that are lacking in the core-hole method. Additionally, we show that in certain systems the supercell core-hole method performs better if the excited electron is added to the background charge. We attribute this improved performance to a reduced self-interaction.
