Hi all, we've solved a large structure (~20,000 residues/asymm unit), with 4-fold ncs and diffraction data to 3.3A. The Rfree/Rfac is ~28%-24% with OK geometry with no major outliers in the Ramachandran plot. I would think I'm done (.. after 6 years!). However, my refined model b-factor (~130A2) is >> Wilson b-factor (~80A2). Obviously I'm not too happy with it. Here is what I tried to resolve this discrepancy: --> play with wxu_scale --> play with B-factor weight in ncs restraint (4-fold ncs) --> play with number of macrocycles --> Redefine tls groups So far nothing really works, except switching from individual_adp to group_adp. However, this increases my Rfree by almost 3%. Any ideas? Thanks in advance, Gino ****************************************************************************** Gino Cingolani, Ph.D. Associate Professor Thomas Jefferson University Dept. of Biochemistry & Molecular Biology 233 South 10th Street - Room 826 Philadelphia PA 19107 Office (215) 503 4573 Lab (215) 503 4595 Fax (215) 923 2117 E-mail: [email protected] ****************************************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e canoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120)