Hi phenix users, I have two questions when using Phenix Refinement. 1. I'd like to run phenix refinement with twin data but I don't know how to define twin_law using GUI Phenix refinement module in Linux. 2. I used phenix refinement in Windows to refine a 2.3A structure. My problem is the Rfree is quite high. - I applied twin refinement + TLS + NCS and SA refinement (wxu_scale = 1) Start: r_work = 0.2149 r_free = 0.2833 bonds = 0.016 angles = 1.988 Final: r_work = 0.2029 r_free = 0.2735 bonds = 0.008 angles = 1.448 - Then I use auto-weight to optimize the Rfree. optimize_xyz_weight = True optimize_adp_weight = True wxc_scale = 0.5 wxu_scale = 1 Start: r_work = 0.2152 r_free = 0.2735 bonds = 0.008 angles = 1.322 Final: r_work = 0.2309 r_free = 0.2781 bonds = 0.003 angles = 0.848 I think the bond rmsd and angle rmsd were too small in this final refinement. Do you think it's normal or I need to try more? Thank you very much for your helpful input. Best wishes, -- * TriNgo * Structural Biology Lab School of Medicine - Sungkyunkwan University Phone: 031-299-6150 Cell: 010-7774-8210