Fig. 2: Simulated static lineshape dominated by chemical shift anisotropy (CSA) interactions.
From: Enabling materials informatics for 29Si solid-state NMR of crystalline materials
Based on this lineshape, the three principal components of the chemical shift tensor can be identified individually as δXX, δYY and δZZ based on the notation from Haeberlen. These values are usually reported as: isotopic chemical shift (δiso), chemical shift anisotropy (ζδ), and the asymmetry parameter (ηCSA). The subplot shows an alternative version of the simulation with δXX and δZZ switched. In this case, the spectrum has a negative value for the anisotropy.
