An efficient density-functional-theory force evaluation for large molecular systems

Simen Reine; Andreas Krapp; Maria Francesca Iozzi; Vebjørn Bakken; Trygve Helgaker; Filip Pawłowski; Pawel Sałek

doi:10.1063/1.3459061

An efficient density-functional-theory force evaluation for large molecular systems

J Chem Phys. 2010 Jul 28;133(4):044102. doi: 10.1063/1.3459061.

Authors

Simen Reine¹, Andreas Krapp, Maria Francesca Iozzi, Vebjørn Bakken, Trygve Helgaker, Filip Pawłowski, Pawel Sałek

Affiliation

¹ 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

PMID: 20687628
DOI: 10.1063/1.3459061

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.