title: Hartree-Fock and density functional complete basis-set (CBS) predicted nuclear shielding anisotropy and shielding tensor components.
abstract: The nuclear shielding anisotropy and shielding tensor components calculated using the hybrid density functional B3PW91 are reported for a model set of compounds comprised of N2, NH3, CH4, C2H4, HCN and CH3CN. An estimation of density functional theory (DFT) and Hartree-Fock complete basis-set limit (CBS) parameters from a 2 (3) point exact fit vs. least-squares fit was obtained with the cc-pVxZ and aug-cc-pVxZ basis sets (x=D, T, Q, 5, 6). Both Hartree-Fock- and DFT-predicted CBS shielding anisotropies and shielding tensor components of the model molecules were in reasonable agreement with available experimental data. The utility of using a limited CBS approach for calculating accurate anisotropic shielding parameters of larger molecules as complementary methods to solid-state NMR is proposed.
authors.affiliation: Chemistry Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439, USA.
authors.forename: Teobald
authors.initials: T
authors.lastname: Kupka
authors.forename: Branko
authors.initials: B
authors.lastname: Ruscic
authors.forename: Robert E
authors.initials: RE
authors.lastname: Botto