Casimir-Polder size consistency -- a constraint violated by some dispersion theories

Tim Gould; Julien Toulouse; János Ángyán; John F. Dobson

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arXiv · 1711.08727

Casimir-Polder size consistency -- a constraint violated by some dispersion theories

Tim Gould·Julien Toulouse·János Ángyán·John F. Dobson

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Abstract

A key goal in quantum chemistry methods, whether ab initio or otherwise, is to achieve size consistency. In this manuscript we formulate the related idea of "Casimir-Polder size consistency" that manifests in long-range dispersion energetics. We show that local approximations in time-dependent density functional theory dispersion energy calculations violate the consistency condition because of incorrect treatment of highly non-local "xc kernel" physics, by up to 10% in our tests on closed-shell atoms.

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Tim Gould, Julien Toulouse, János Ángyán, John F. Dobson. 2017-11-23. Casimir-Polder size consistency -- a constraint violated by some dispersion theories. https://arxiv.org/abs/1711.08727

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