Calculation of solid-state NMR lineshapes using contour analysis.
Two new methods for calculating lineshapes in solid-state NMR spectra are described. The first method, which we refer to as semi-analytical, allows the rapid calculation of quadrupolar central-transition lineshapes in both static and magic-angle spinning cases. The second method, which is fully numerical, allows the calculation of lineshapes resulting from any combination of interactions, including quadrupolar, dipolar and chemical shift anisotropy, and is not restricted to cases in which the principal axis systems for the different interactions are aligned. Both methods are derived from consideration of the contour lines on a plot of the resonance frequency against the Euler angles, allowing the intensity of the lineshape to be calculated at each frequency. Consequently, highly accurate lineshapes can be calculated more rapidly than previously possible, since only orientations contributing to each specific frequency are considered. For our semi-analytical method, the intensity of each point in the lineshape can be directly calculated in tens of milliseconds on a standard PC. In contrast, established methods can take several hours to calculate the same lineshape.
School of Chemistry, Cardiff University, Park Place, Cardiff, Wales CF10 3AT, UK. Electronic address: HughesCE@cardiff.ac.uk.
Colan E
CE
Hughes
School of Chemistry, Cardiff University, Park Place, Cardiff, Wales CF10 3AT, UK. Electronic address: HarrisKDM@cardiff.ac.uk.
Kenneth D M
KD
Harris