QuadFit

From NMR Wiki

QuadFit is a cross-platform program designed for use with spectra obtained of powders via solid-state NMR. QuadFit is capable of simulating distributions of both Quadrupolar and CSA interaction parameters acquired under both MAS and static conditions. QuadFit is also capable of simulating spectra obtained from integer spin nuclei.

QuadFit was written and is maintained by Dr Thomas F. Kemp from the Solid-State NMR Group at the University of Warwick and is available from here.