arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.07727cond-mat.mtrl-scicond-mat.str-el
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适用于金属和半导体的全电子线性缀加平面波 GW 方法

All electron GW with linearized augmented plane waves for metals and semiconductors

Kristjan Haule, Subhasish Mandal

AI总结:

本文在全电子线性缀加平面波框架中实现 GW 算法,重点解决金属费米面奇异性、动量网格收敛和芯态处理,并在多种金属与绝缘体上验证其准确性。

摘要:

GW 近似是最受欢迎的无参数多体方法之一,它突破了标准密度泛函理论(DFT)的局限,可用于确定中等关联材料、尤其是半导体的激发谱。它也是将图解 Monte Carlo 方法发展为电子结构工具的第一步,后者有望为固态问题提供数值精确的解。目前,大多数电子结构软件包都支持对带绝缘材料进行 GW 计算,但对金属体系的支持仍仅限于少数实现。金属体系对 GW 而言颇具挑战,因为这需要精确分辨费米面粉奇点,从而要求采用稠密的动量网格。在此,我们在全电子线性缀加平面波框架内实现了 GW 算法,并特别关注金属体系、关于动量网格的收敛性,以及对深层芯态的恰当处理,以满足未来变分图解 Monte Carlo 实现的需要。我们改进的用于分辨费米面粉奇点的算法,使我们能够对虚轴数据进行稳定而精确的解析延拓;该延拓在金属和绝缘材料中贯穿整个 Brillouin 区对 GW 激发谱实施,并与数值上更稳定的围道形变积分技术进行了比较。我们计算了元素金属体系 Li、Na 和 Mg,以及 Si、BN、SiC、MgO、LiF、ZnS 和 CdS 等各种窄带隙和宽带隙绝缘体的能带结构,并将我们的结果与以往的 GW 计算和可用的实验数据进行了比较。我们的结果与现有文献吻合良好。

英文摘要:

GW approximation is one of the most popular parameter-free many-body methods that goes beyond the limitations of the standard density functional theory (DFT) to determine the excitation spectra for moderately correlated materials and in particular the semiconductors. It is also the first step in developing the diagrammatic Monte Carlo method into an electronic structure tool, which would offer a numerically exact solution to the solid-state problem. Currently, most electronic structure packages support GW calculations for the band-insulating materials, while the support for the metallic system remains limited to only a few implementations. The metallic systems are challenging for GW, as it requires one to accurately resolve the Fermi surface singularities, which demands a dense momentum mesh. Here we implement GW algorithm within the all-electron Linear Augmented Plane Wave framework, where we pay special attention to the metallic systems, the convergence with respect to momentum mesh and proper treatment of the deep laying core states, as needed for the future variational diagrammatic Monte Carlo implementation. Our improved algorithm for resolving Fermi surface singularities allows us a stable and accurate analytic continuation of imaginary axis data, which is carried out for GW excitation spectra throughout the Brillouin zone in both the metallic and insulating materials, and is compared to numerically more stable contour deformation integration technique. We compute band structures for elemental metallic systems Li, Na, and Mg as well as for various narrow and wide bandgap insulators such as Si, BN, SiC, MgO, LiF, ZnS, and CdS and compare our results with previous GW calculations and available experiments data. Our results are in good agreement with the available literature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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