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arXiv 1809.02183math.NAcs.NA
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用密度矩阵研究自洽场迭代的收敛性

A density matrix approach to the convergence of the self-consistent field iteration

Royal Institute of Technology(皇家理工学院);Uppsala University(乌普萨拉大学)

Parikshit Upadhyaya, Elias Jarlebring, Emanuel H. Rubensson

AI总结:

本文通过密度矩阵作为固定点迭代的状态,对自洽场(SCF)迭代的局部收敛性进行了分析,提出了局部收敛的充分条件和几乎必要条件,探讨了收敛性与问题特性之间的关系,并通过示例分析了收敛因子的上界与实际收敛行为的差异。

摘要:

在本文中,我们通过将密度矩阵作为固定点迭代的状态,对自洽场(SCF)迭代的局部收敛性进行了分析。利用固定点映射的雅可比矩阵的谱半径,提出了局部收敛的充分条件和几乎必要条件。通过推导以更高间隙为表达式的上界,探讨了收敛性与问题某些性质之间的关系。这提供了更多关于问题特征值间隙如何影响收敛性的信息,因此这些上界比标准收敛结果更具洞察力。我们还对一个示例进行了详细分析,描述了上界与精确收敛因子之间的差异。最后,我们给出了数值示例,比较了精确收敛因子值与SCF观察到的行为,以及我们新的上界和使用更高间隙的特征化。在界限未能准确捕捉收敛性的情况下,我们还提供了启发式的收敛因子估计。

英文摘要:

In this paper, we present a local convergence analysis of the self-consistent field (SCF) iteration using the density matrix as the state of a fixed-point iteration. Sufficient and almost necessary conditions for local convergence are formulated in terms of the spectral radius of the Jacobian of a fixed-point map. The relationship between convergence and certain properties of the problem is explored by deriving upper bounds expressed in terms of higher gaps. This gives more information regarding how the gaps between eigenvalues of the problem affect the convergence, and hence these bounds are more insightful on the convergence behaviour than standard convergence results. We also provide a detailed analysis to describe the difference between the bounds and the exact convergence factor for an illustrative example. Finally we present numerical examples and compare the exact value of the convergence factor with the observed behaviour of SCF, along with our new bounds and the characterization using the higher gaps. We provide heuristic convergence factor estimates in situations where the bounds fail to well capture the convergence.

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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