Dear all, I am refining a structure to 2.9 A, with pretty bad experimental data (P1, ~5400 residues in the A.U. (4 mol), anisotropic, fairly incomplete...). I have been running phenix.refine with NCS, 1 ADP per residue, lower target weights, TLS. My R/Rfree are stuck at about 2.4/3.05. I was getting around 2% ramachandran outliers at every cycle so I have been giving the nightly builds a shot. Now I get 0.2% outliers without changing any parameters for the ramachandra_restraints but it is forcing some of the peptide bonds out of the density. What can I tweak to improve the refinement? Thanks all in advance! Jose José Trincão, PhD CQFB@FCT-UNL 2829-516 Caparica, Portugal "It's very hard to make predictions... especially about the future" - Niels Bohr