title: Subsystem density functional theory with meta-generalized gradient approximation exchange-correlation functionals.
abstract: We analyze the methodology and the performance of subsystem density functional theory (DFT) with meta-generalized gradient approximation (meta-GGA) exchange-correlation functionals for non-bonded molecular systems. Meta-GGA functionals depend on the Kohn-Sham kinetic energy density (KED), which is not known as an explicit functional of the density. Therefore, they cannot be directly applied in subsystem DFT calculations. We propose a Laplacian-level approximation to the KED which overcomes this limitation and provides a simple and accurate way to apply meta-GGA exchange-correlation functionals in subsystem DFT calculations. The so obtained density and energy errors, with respect to the corresponding supermolecular calculations, are comparable with conventional approaches, depending almost exclusively on the approximations in the non-additive kinetic embedding term. An embedding energy error decomposition explains the accuracy of our method.
authors.affiliation: Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Śmiga
authors.affiliation: Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT), Via per Arnesano 16, I-73100 Lecce, Italy.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fabiano
authors.affiliation: Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.
authors.forename: Savio
authors.initials: S
authors.lastname: Laricchia
authors.affiliation: Center for Biomolecular Nanotechnologies@UNILE, Istituto Italiano di Tecnologia (IIT), Via Barsanti, 73010 Arnesano, LE, Italy.
authors.forename: Lucian A
authors.initials: LA
authors.lastname: Constantin
authors.affiliation: Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT), Via per Arnesano 16, I-73100 Lecce, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Della Sala
mesh_terms: D007700:Kinetics; D011789:Quantum Theory