title: An efficient density-functional-theory force evaluation for large molecular systems.
abstract: An efficient, linear-scaling implementation of Kohn-Sham density-functional theory for the calculation of molecular forces for systems containing hundreds of atoms is presented. The density-fitted Coulomb force contribution is calculated in linear time by combining atomic integral screening with the continuous fast multipole method. For higher efficiency and greater simplicity, the near-field Coulomb force contribution is calculated by expanding the solid-harmonic Gaussian basis functions in Hermite rather than Cartesian Gaussians. The efficiency and linear complexity of the molecular-force evaluation is demonstrated by sample calculations and applied to the geometry optimization of a few selected large systems.
authors.affiliation: Department of Chemistry, Centre for Theoretical and Computational 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: Andreas
authors.initials: A
authors.lastname: Krapp
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Iozzi
authors.forename: Vebjørn
authors.initials: V
authors.lastname: Bakken
authors.forename: Trygve
authors.initials: T
authors.lastname: Helgaker
authors.forename: Filip
authors.initials: F
authors.lastname: Pawłowski
authors.forename: Pawel
authors.initials: P
authors.lastname: Sałek