The static NMR lineshape is already motionally narrowed at room temperature (SI Figure ). At higher temperatures sharp features appear in the satellites which can be fit by residual quadrupolar coupling (6 kHz) combined with chemical shift anisotropy (SI Figure , span 3 ppm, skew  of -0.76). Less pronounced but similar features are observed for the Zrsubstituted samples (SI Figure ). This can be interpreted in two ways: Either, the motion averages out the chemical shift anisotropy more effectively in the doped samples (but not fully), or this is an effect of the more disordered local environment due to the Zr-dopant.