title: Variational and robust density fitting of four-center two-electron integrals in local metrics.
abstract: Density fitting is an important method for speeding up quantum-chemical calculations. Linear-scaling developments in Hartree-Fock and density-functional theories have highlighted the need for linear-scaling density-fitting schemes. In this paper, we present a robust variational density-fitting scheme that allows for solving the fitting equations in local metrics instead of the traditional Coulomb metric, as required for linear scaling. Results of fitting four-center two-electron integrals in the overlap and the attenuated Gaussian damped Coulomb metric are presented, and we conclude that density fitting can be performed in local metrics at little loss of chemical accuracy. We further propose to use this theory in linear-scaling density-fitting developments.
authors.affiliation: Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway. simen.reine@kjemi.uio.no
authors.forename: Simen
authors.initials: S
authors.lastname: Reine
authors.forename: Erik
authors.initials: E
authors.lastname: Tellgren
authors.forename: Andreas
authors.initials: A
authors.lastname: Krapp
authors.forename: Thomas
authors.initials: T
authors.lastname: Kjaergaard
authors.forename: Trygve
authors.initials: T
authors.lastname: Helgaker
authors.forename: Branislav
authors.initials: B
authors.lastname: Jansik
authors.forename: Stinne
authors.initials: S
authors.lastname: Host
authors.forename: Paweł
authors.initials: P
authors.lastname: Salek