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arXiv 1701.04643cond-mat.mtrl-scics.NAmath.NAphysics.comp-ph
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电子结构计算中的离散化误差抵消:定量研究

Discretization error cancellation in electronic structure calculation: a quantitative study

CERMICS, Ecole des Ponts and INRIA Paris(法国国立路桥学校计算数学与控制系统系 和 巴黎国家信息与自动化研究所);Sorbonne Universités, UPMC Univ. Paris 06 and CNRS, UMR 7598, Laboratoire Jacques-Louis Lions(索邦大学、巴黎第六大学 和 法国国家科学研究中心,雅克-路易·利翁斯实验室);Sorbonne Universités, UPMC Univ. Paris 06, Institut du Calcul et de la Simulation(索邦大学、巴黎第六大学,计算与模拟研究所)

Eric Cancès, Geneviève Dusson

AI总结:

本文通过数值模拟和解析分析,研究了电子结构计算中离散化误差抵消现象,揭示了能量差与能量本身的误差收敛特性。

摘要:

本文通过数值模拟和解析分析,研究了电子结构计算中离散化误差抵消现象,揭示了能量差与能量本身的误差收敛特性。

英文摘要:

It is often claimed that error cancellation plays an essential role in quantum chemistry and first-principle simulation for condensed matter physics and materials science. Indeed, while the energy of a large, or even medium-size, molecular system cannot be estimated numerically within chemical accuracy (typically 1 kcal/mol or 1 mHa), it is considered that the energy difference between two configurations of the same system can be computed in practice within the desired accuracy. The purpose of this paper is to provide a quantitative study of discretization error cancellation. The latter is the error component due to the fact that the model used in the calculation (e.g. Kohn-Sham LDA) must be discretized in a finite basis set to be solved by a computer. We first report comprehensive numerical simulations performed with Abinit on two simple chemical systems, the hydrogen molecule on the one hand, and a system consisting of two oxygen atoms and four hydrogen atoms on the other hand. We observe that errors on energy differences are indeed significantly smaller than errors on energies, but that these two quantities asymptotically converge at the same rate when the energy cut-off goes to infinity. We then analyze a simple one-dimensional periodic Schrödinger equation with Dirac potentials, for which analytic solutions are available. This allows us to explain the discretization error cancellation phenomenon on this test case with quantitative mathematical arguments.

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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