I am refining a 2.0 A structure in Phenix using mostly the graphical interface. The maps are very good and the R factors are low (0.208/0.173). But the geometry is not so great with bond deviations of 0.208 and Angle deviations of 1.85. What is the best thing to do to try to improve the geometry. Should I try to optimize the weights? The other question is about adding hydrogens to the model. I did add them in a previous refinement cycle. After rebuilding the model in coot, most of the model still has the hydrogens in the input file for the next refinement cycle, but some residues and waters don't have hydrogens. When I tried to add hydrogens again to the model, I got an error message about atoms being to close. Does Phenix know where to add hydrogens if the input model has already hydroegns on many residues? Thanks Ursula -- Ursula Schulze-Gahmen, PhD. QB3, Tjian Lab MCB, 16 Barker Hall #3204 University of California Berkeley Berkeley, CA 94720-3204 Phone: (510) 642 8258 [email protected]