Restoring Size Consistency of Approximate Functionals Constructed from the Adiabatic Connection

Stefan Vuckovic*, Paola Gori-Giorgi, Fabio Della Sala, Eduardo Fabiano

*Corresponding author for this work

Research output: Contribution to JournalArticle

Abstract

Approximate exchange-correlation functionals built by modeling in a nonlinear way the adiabatic connection (AC) integrand of density functional theory have many attractive features, being virtually parameter-free and satisfying different exact properties, but they also have a fundamental flaw: they violate the size-consistency condition, crucial to evaluate interaction energies of molecular systems. We show that size consistency in the AC-based functionals can be restored in a very simple way at no extra computational cost. Results on a large set of benchmark molecular interaction energies show that functionals based on the interaction strength interpolation approximations are significantly more accurate than second-order perturbation theory.

Original languageEnglish
Pages (from-to)3137-3142
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume9
Issue number11
Early online date22 May 2018
DOIs
Publication statusPublished - 7 Jun 2018

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