Efficient polynomial analysis of magic-angle spinning sidebands and application to order parameter determination in anisotropic samples

Abstract. Chemical shift tensors in 13C solid-state NMR provide valuable localized information on the chemical bonding environment organic matter, and deviations from isotropic static-limit powder line shapes sensitively encode dynamic-averaging or orientation effects. Studies natural abundance require magic-angle spinning (MAS), where analysis must thus focus sidebands. We propose an alternative fitting procedure for sidebands based upon a polynomial expansion that is more efficient than common numerical solution of average. The approach plays out its advantages determination CST (chemical-shift tensor) principal values spinning-sideband intensities order parameters non-isotropic samples, which here illustrated with example stretched glassy polycarbonate.