Few tips that will save your time when using Relax* ( https://www.nmr-relax.com ). *d'Auvergne, E. J. and Gooley, P. R. (2008). Optimisation of NMR dynamic models I. Minimisation algorithms and their performance within the model-free and Brownian rotational diffusion spaces. J. Biomol. NMR , 40 (2), 107-119. *d'Auvergne, E. J. and Gooley, P. R. (2008). Optimisation of NMR dynamic models II. A new methodology for the dual optimisation of the model-free parameters and the Brownian rotational diffusion tensor. J. Biomol. NMR , 40 (2), 121-133. FILES to load: NOE, R1, R2, pdb Format of NOE/Rs: name of protein / number / residue / number / atom (N) / value / error COMT 1 GLN 1 N 1.055199602 0.047908918 COMT 2 GLY 2 N 0.628859626 0.020470979 COMT 4 THR 4 N 0.649051411 0.023684093 COMT 5 LYS 5 N 0.668918693 0.04637887 Relax doesn't like negative values. Delete if you have any negative