Dear all I processed my images in point group P 3 2 1. After running Phaser and building it, the space group was P 3(2) 2 1. However, the refinement is stuck with Rfree at around 35-38 % (data extending to 3.3 A). As I believe the R factor is a bit high, and I have a different crystal form in P4(2) 2(1) 2 with R free at 25 % for data to 3.8 A, I expanded it to P 1, redid Phaser searching for 48 copies. After refinement, the R free is at 38 %. For some reason, Zanuda/Refmac is not able to read my files. So I ran Xtriage instead: A summary of R values for various possible point groups follow. ------------------------------------------------------------------------------------------------------- | Point group | mean R_used | max R_used | mean R_unused | min R_unused | BIC | choice | ------------------------------------------------------------------------------------------------------- | P 3 | 0.000 | 0.000 | 0.271 | 0.000 | 3.521e+05 | | | C 1 2 1 (2*y,-x+y,z) | 0.423 | 0.423 | 0.200 | 0.000 | 1.763e+06 | | | P 1 | None | None | 0.219 | 0.000 | 1.056e+06 | | | P 6 | 0.242 | 0.423 | 0.200 | 0.000 | 1.365e+06 | | | C 2 2 2 (x+y,2*y,z) | 0.271 | 0.423 | 0.200 | 0.000 | 1.464e+06 | | | P 3 2 1 | 0.000 | 0.000 | 0.423 | 0.423 | 1.761e+05 | | | P 3 1 2 | 0.242 | 0.423 | 0.200 | 0.000 | 1.365e+06 | | | C 2 2 2 (2*x,x+y,z) | 0.271 | 0.423 | 0.200 | 0.000 | 1.464e+06 | | | P 1 1 2 | 0.423 | 0.423 | 0.200 | 0.000 | 1.763e+06 | | | P 6 2 2 | 0.219 | 0.423 | None | None | 1.265e+06 | | | C 1 2 1 (x+y,-x+y,z) | 0.000 | 0.000 | 0.242 | 0.000 | 5.282e+05 | | | C 1 2 1 (x+y,2*y,z) | 0.423 | 0.423 | 0.200 | 0.000 | 1.763e+06 | | | C 1 2 1 (x-y,2*x,z) | 0.000 | 0.000 | 0.242 | 0.000 | 5.282e+05 | | | C 2 2 2 (x-y,x+y,z) | 0.271 | 0.423 | 0.200 | 0.000 | 1.464e+06 | | | C 1 2 1 (2*x,x+y,z) | 0.000 | 0.000 | 0.242 | 0.000 | 5.282e+05 | | | C 1 2 1 (x-y,x+y,z) | 0.423 | 0.423 | 0.200 | 0.000 | 1.763e+06 | | ------------------------------------------------------------------------------------------------------- R_used: mean and maximum R value for symmetry operators *used* in this point group R_unused: mean and minimum R value for symmetry operators *not used* in this point group Looking at the R values, it is possible that it is actually C 1 2 1. My questions: 1. What is the difference between the C 1 2 1 lines? What do the values in brackets mean? 2. Since Xtriage did indicate a possible NCS axis parallel to crystallographic axis (and it looks almost like that in my P321 model), do I reintegrate in one of those C121 and then redo Phaser/refinement? I can post a screenshot of model if that will help. Thanks. Mohamed