Hello, I have a good data set to 1.8 A and refined it with the actual version of phenix, including annealing and isotropic bfactors. Checking the B factor variance in coot revealed high differences in about 50% of the residues. Most of them are at the surface, but still there are residues like phenylalanines and valines within the core where the bfactors jump from 25 to 50 from one carbon atom to the other. Changing wu and wxu_scale did not improve the results. A quick check with refmac improved the results, so i guess I am missing the right restraints for phenix. Which parameters should be changed to improve the bfactor variance in phenix? Thanks for your help Daniel Daniel Frey Department of Biochmistry University of Zurich Winterthurerstrass 190 8057 Zurich Switzerland [email protected] Tel: +41446355558 www.biochem.uzh.ch/gruetter www.structuralbiology.uzh.ch