Hi Pavel I need some help advice regarding anisotropic refinement, which I've never done before. My current Rfactors are R-work = 0.1587, R-free = 0.1726, resolution 1.26 Å. I have TLS groups, and know I need to exclude these from individual anisotropic refinement. Questions: 1) how to decide my atom selection for anisotropic refinement. I've identified segments with MC B below 20, but what to do for surface residues which have well ordered MC but B factors for side chains increase (e.g. along a well ordered Lys side chain) - should (can?) I a) refine only MC anisotropically, b) refine whole residue anisotropically, c) refine isotropic 2) How to write a a parameter file for phenix.refine defining the atom selections. The residues I'd like to use for anisotropic refinement are: A7-A44 A61-A149 A173-A182 A202-A254 A263-A290 all in chain A I found following on phenix.refine online docs, but am not sure to to extend this for a more complex selection needed above, which Ideally I'd put into a file to be read in when I start refinement. Could yo show me how to do for A7-A44 and A61-A149, and I'll follow example for the rest. adp.individual.anisotropic="resid 1:2 and not element H" adp.individual.isotropic="not (resid 1:2 and not element H) Thanks for help. Mark . -- +++++++++++++++++++++++++++++++++++++++++++++++++++++++ Mark Mayer Ph.D. LCMN NICHD NIH DHHS Bldg 35, Room 3B 1002 MSC 3712 35 Lincoln Drive Bethesda MD 20892 3712 Phone: 301-496-9346 (office); 301-496-9347 (lab); FAX 301-496-2396 Lab web site: http://snb.nichd.nih.gov/index.htm Send packages, Fedex and anything requiring a signature to: Bldg 35, Room 3B 1004 35 Lincoln Drive Bethesda MD 20892