title: Theory and applications of supercycled symmetry-based recoupling sequences in solid-state nuclear magnetic resonance.
abstract: We present the theoretical principles of supercycled symmetry-based recoupling sequences in solid-state magic-angle-spinning NMR. We discuss the construction procedure of the SR26 pulse sequence, which is a particularly robust sequence for double-quantum homonuclear dipole-dipole recoupling. The supercycle removes destructive higher-order average Hamiltonian terms and renders the sequence robust over long time intervals. We demonstrate applications of the SR26 sequence to double-quantum spectroscopy, homonuclear spin counting, and determination of the relative orientations of chemical shift anisotropy tensors.
authors.affiliation: Department of Molecular Biosciences, University of Oslo, P.O. Box 1041-Blindern, 0316 Oslo, Norway.
authors.forename: Per Eugen
authors.initials: PE
authors.lastname: Kristiansen
authors.forename: Marina
authors.initials: M
authors.lastname: Carravetta
authors.forename: Jacco D
authors.initials: JD
authors.lastname: van Beek
authors.forename: Wai Cheu
authors.initials: WC
authors.lastname: Lai
authors.forename: Malcolm H
authors.initials: MH
authors.lastname: Levitt