Hi Troels, I just wanted to point out something about your recent additions to the relax wiki at http://wiki.nmr-relax.com/B14#Comments_from_the_Author. The part about off-resonance effects in the CPMG is also listed at the top of the relaxation dispersion 'to do' section of the manual (http://www.nmr-relax.com/manual/do_dispersion_features_yet_be_implemented.html). Note that the addition of such a feature to the numeric CPMG models would need significant testing against the CATIA software from Flemming Hansen, i.e. the CATIA data input creation and CATIA control user functions in relax would need improvement, and some good test data sets. It should be put into a different numeric model as the evolution matrix will be different. That would also allow rigorous comparisons of the off-resonance effect in the CPMG. However I don't expect that this feature will be added to relax in the near future, despite its clear benefits for the final results. Regards, Edward