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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 initiate the quantitative study of discretization error cancellation. Discretization error 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 [X. Gonze, B. Amadon, P.-M. Anglade et al., Comput. Phys. Commun. 180 (2009) 2582–2615; X. Gonze, J.-M. Beuken, R. Caracas et al., Comput. Materials Sci. 25 (2002) 478–492] 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.
Cancès, Eric 1 ; Dusson, Geneviève 2
@article{M2AN_2017__51_5_1617_0,
author = {Canc\`es, Eric and Dusson, Genevi\`eve},
title = {Discretization error cancellation in electronic structure calculation: toward a quantitative study},
journal = {ESAIM: Mathematical Modelling and Numerical Analysis },
pages = {1617--1636},
publisher = {EDP-Sciences},
volume = {51},
number = {5},
year = {2017},
doi = {10.1051/m2an/2017035},
mrnumber = {3731543},
zbl = {1382.82003},
language = {en},
url = {http://geodesic.mathdoc.fr/articles/10.1051/m2an/2017035/}
}
TY - JOUR AU - Cancès, Eric AU - Dusson, Geneviève TI - Discretization error cancellation in electronic structure calculation: toward a quantitative study JO - ESAIM: Mathematical Modelling and Numerical Analysis PY - 2017 SP - 1617 EP - 1636 VL - 51 IS - 5 PB - EDP-Sciences UR - http://geodesic.mathdoc.fr/articles/10.1051/m2an/2017035/ DO - 10.1051/m2an/2017035 LA - en ID - M2AN_2017__51_5_1617_0 ER -
%0 Journal Article %A Cancès, Eric %A Dusson, Geneviève %T Discretization error cancellation in electronic structure calculation: toward a quantitative study %J ESAIM: Mathematical Modelling and Numerical Analysis %D 2017 %P 1617-1636 %V 51 %N 5 %I EDP-Sciences %U http://geodesic.mathdoc.fr/articles/10.1051/m2an/2017035/ %R 10.1051/m2an/2017035 %G en %F M2AN_2017__51_5_1617_0
Cancès, Eric; Dusson, Geneviève. Discretization error cancellation in electronic structure calculation: toward a quantitative study. ESAIM: Mathematical Modelling and Numerical Analysis , Tome 51 (2017) no. 5, pp. 1617-1636. doi: 10.1051/m2an/2017035
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