Hi, I'm refining a 2.88 Angstrom structure and am getting a difference of greater than 6% between the R-work and R-free. The best result (I think) is what I have from minimization alone: Start R-work = 0.3219, R-free = 0.3505 (no bulk solvent and anisotropic scale) Final R-work = 0.2424, R-free = 0.3174 (no bulk solvent and anisotropic scale) Start R-work = 0.3220, R-free = 0.3500 Final R-work = 0.2411, R-free = 0.3176 The results from simulated annealing are the following: Start R-work = 0.3219, R-free = 0.3505 (no bulk solvent and anisotropic scale) Final R-work = 0.2454, R-free = 0.3322 (no bulk solvent and anisotropic scale) Start R-work = 0.3220, R-free = 0.3500 Final R-work = 0.2403, R-free = 0.3333 I have also done the refinement with ncs but ncs is probably not appropriate for my structure. The final R-free ends up being higher (though the difference between R-free and R-work ends up being 6-7%) My PI (who is on vacation until next week) said that it was a problem if R-work was more than 0.06 lower than R-free. Any recommendations for me? Is it possible to reduce this difference? Is it worth it to rebuild the refined pdb if the R-work is this different from the R-free? My refinement script is: phenix.refine ss46_p3_cv.mtz ss46_rebuilt.pdb \ output.prefix=results/ss46_rebuilt_sa \ strategy=individual_sites+group_adp cif_link.params nag-nag.cif \ twin_law="h,-h-k,-l" \ simulated_annealing=true (the cif_link.params and nag-nag.cif files are made to handle the N-glycosylation sites, I think). Thanks for your help! -Sam