title: Systematic Improvement of Density Functionals through Parameter-Free Hybridization Schemes.
abstract: It is suggested here that the ultimate accuracy of DFT methods arises from the type of hybridization scheme followed. This idea can be cast into a mathematical formulation utilizing an integrand connecting the noninteracting and the interacting particle system. We consider two previously developed models for it, dubbed as HYB0 and QIDH, and assess a large number of exchange-correlation functionals against the AE6, G2/148, and S22 reference data sets. An interesting consequence of these hybridization schemes is that the error bars, including the standard deviation, are found to markedly decrease with respect to the density-based (nonhybrid) case. This improvement is substantially better than variations due to the underlying density functional used. We thus finally hypothesize about the universal character of the HYB0 and QIDH models.
authors.affiliation: CompuNet, Istituto Italiano di Tecnologia , via Morego 30, I-16163 Genoa, Italy.
authors.forename: Éric
authors.initials: É
authors.lastname: Brémond
authors.affiliation: CompuNet, Istituto Italiano di Tecnologia , via Morego 30, I-16163 Genoa, Italy.
authors.forename: Marika
authors.initials: M
authors.lastname: Savarese
authors.affiliation: Departamento de Química Física, Universidad de Alicante , E-03080 Alicante, Spain.
authors.forename: Ángel José
authors.initials: ÁJ
authors.lastname: Pérez-Jiménez
authors.affiliation: Departamento de Química Física, Universidad de Alicante , E-03080 Alicante, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Sancho-García
authors.affiliation: CompuNet, Istituto Italiano di Tecnologia , via Morego 30, I-16163 Genoa, Italy.|Institut de Recherche de Chimie Paris, IRCP CNRS UMR-8247, École Nationale Supérieure de Chimie de Paris, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05, France.|Institut Universitaire de France , 103 Boulevard Saint Michel, F-75005 Paris, France.
authors.forename: Carlo
authors.initials: C
authors.lastname: Adamo
keywords: density functional approximations; double hybrids; exchange-correlation integrands; global hybrids; parameter-free functionals