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arXiv 2312.02459cond-mat.mtrl-sciphysics.comp-ph
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一种用于自洽场迭代和广义层错能计算的自适应预处理方案

An adaptive preconditioning scheme for the self-consistent field iteration and generalized stacking-fault energy calculations

Sitong Zhang, Xingyu Gao, Haifeng Song, Bin Wen

AI总结:

本文提出一种自适应预处理方案,在SCF迭代中自动识别长波发散并开启Kerker预处理,在Elk-7.2.42中实现,用于计算Al、Cu、Si的广义层错能,证明三位移超胞模型在保证精度下收敛更快。

摘要:

广义层错能(GSFE)是材料塑性变形的基本但关键的参数。我们采用全势线性化缀加平面波(FLAPW)方法进行第一性原理计算,基于单位移和三位移超胞模型评估广义层错能。两种模型中引入了不同程度的缺陷,从而影响自洽场(SCF)迭代的收敛性。我们提出了一种自适应预处理方案,该方案能够在SCF迭代过程中识别雅可比矩阵的长波发散行为,并自动开启Kerker预处理以加速收敛。我们在Elk-7.2.42软件包中实现了该算法,并计算了Al、Cu和Si(111)面<-1-12>方向的广义层错能曲线。我们发现,单位移和三位移超胞模型具有等效的计算精度,且均在实验数据的不确定度范围内。就计算效率而言,三位移超胞模型更优,因为其收敛性更好,与单位移超胞模型相比表现出更低的缺陷程度。

英文摘要:

The generalized stacking-fault energy (GSFE) is the fundamental but key parameter for the plastic deformation of materials. We perform first-principles calculations by full-potential linearized augmented planewave (FLAPW) method to evaluate the GSFE based on the single-shift and triple-shift supercell models. Different degrees of defects are introduced in the two models, thereby affecting the convergence of the self-consistent field (SCF) iterations. We present an adaptive preconditioning scheme which can identify the long-wavelength divergence behavior of the Jacobian during the SCF iteration and automatically switch on the Kerker preconditioning to accelerate the convergence. We implement this algorithm in Elk-7.2.42 package and calculate the GSFE curves for Al, Cu, and Si (111) plane <-1-12> direction. We found that the single-shift and triple-shift supercell models have equivalent calculation accuracy and are within the experimental data uncertainty. For computational efficiency, the triple-shift supercell model is preferable due to its better convergence, exhibiting lower degree of defect compared to the single-shift supercell model.

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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