title: Double-hybrid density-functional theory made rigorous.
abstract: We provide a rigorous derivation of a class of double-hybrid approximations, combining Hartree-Fock exchange and second-order Møller-Plesset correlation with a semilocal exchange-correlation density functional. These double-hybrid approximations contain only one empirical parameter and use a density-scaled correlation energy functional. Neglecting density scaling leads to a one-parameter version of the standard double-hybrid approximations. We assess the performance of these double-hybrid schemes on representative test sets of atomization energies and reaction barrier heights, and we compare to other hybrid approximations, including range-separated hybrids. Our best one-parameter double-hybrid approximation, called 1DH-BLYP, roughly reproduces the two parameters of the standard B2-PLYP or B2GP-PLYP double-hybrid approximations, which shows that these methods are not only empirically close to an optimum for general chemical applications but are also theoretically supported.
authors.affiliation: Laboratoire de Chimie Théorique, Université Pierre et Marie Curie and CNRS, 75005 Paris, France. kamal.sharkas@etu.upmc.fr
authors.forename: Kamal
authors.initials: K
authors.lastname: Sharkas
authors.forename: Julien
authors.initials: J
authors.lastname: Toulouse
authors.forename: Andreas
authors.initials: A
authors.lastname: Savin
mesh_terms: D008956:Models, Chemical; D011789:Quantum Theory