title: Nuclei-selected atomic-orbital response-theory formulation for the calculation of NMR shielding tensors using density-fitting.
abstract: An atomic orbital density matrix based response formulation of the nuclei-selected approach of Beer, Kussmann, and Ochsenfeld [J. Chem. Phys. 134, 074102 (2011)] to calculate nuclear magnetic resonance (NMR) shielding tensors has been developed and implemented into LSDalton allowing for a simultaneous solution of the response equations, which significantly improves the performance. The response formulation to calculate nuclei-selected NMR shielding tensors can be used together with the density-fitting approximation that allows efficient calculation of Coulomb integrals. It is shown that using density-fitting does not lead to a significant loss in accuracy for both the nuclei-selected and the conventional ways to calculate NMR shielding constants and should thus be used for applications with LSDalton.
authors.affiliation: Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway.
authors.forename: Chandan
authors.initials: C
authors.lastname: Kumar
authors.affiliation: Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kjærgaard
authors.affiliation: Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway.
authors.forename: Trygve
authors.initials: T
authors.lastname: Helgaker
authors.affiliation: Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway.
authors.forename: Heike
authors.initials: H
authors.lastname: Fliegl