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arXiv 1302.6022physics.comp-ph
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Kohn-Sham密度泛函理论中自洽场迭代的收敛性

On the Convergence of the Self-Consistent Field Iteration in Kohn-Sham Density Functional Theory

Xin Liu, Xiao Wang, Zaiwen Wen, Yaxiang Yuan

摘要:

求解Kohn-Sham(KS)方程的自洽场(SCF)迭代法常常不能收敛,但至今没有明确的解释。在本文中,我们研究SCF迭代从最小化相应的KS总能量泛函的角度。通过分析KS总能量泛函的二阶Taylor展开式,估计了哈密顿量与SCF迭代中未使用的Hessian部分之间的关系,我们能够证明从任意初始点的全局收敛性和从足够接近KS方程解的初始点的局部线性收敛性。状态足够大,并且交换相关泛函的二阶导数从上面一致有界。虽然这些条件是非常严格的,几乎从来没有满足现实中,我们的分析是有趣的,在这个意义上,它提供了一个定性的预测的行为的SCF迭代。

英文摘要:

It is well known that the self-consistent field (SCF) iteration for solving the Kohn-Sham (KS) equation often fails to converge, yet there is no clear explanation. In this paper, we investigate the SCF iteration from the perspective of minimizing the corresponding KS total energy functional. By analyzing the second-order Taylor expansion of the KS total energy functional and estimating the relationship between the Hamiltonian and the part of the Hessian which is not used in the SCF iteration, we are able to prove global convergence from an arbitrary initial point and local linear convergence from an initial point sufficiently close to the solution of the KS equation under assumptions that the gap between the occupied states and unoccupied states is sufficiently large and the second-order derivatives of the exchange correlation functional are uniformly bounded from above. Although these conditions are very stringent and are almost never satisfied in reality, our analysis is interesting in the sense that it provides a qualitative prediction of the behavior of the SCF iteration.

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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