Hello, I using the latest stable build of phenx.refine (1.8.4) I recently collected data, processed and obtained an MR solution using phaser. I am stuck trying to refine with an Rfree sitting at 40% I really want to know if the high Rfree is due to poor data quality or if non-crystallographic symmetry involving a near perfect two fold rotation between the two molecules in the ASU could somehow impede refinement. Stats and other information is below. Thank you for any help you can give. -Yarrow Visually, the quality of the data is marginal at best (streaky/ice rings in many frames) despite good processing stats from XDS. Processing with mosflm or HKL2000 managed to index but failed pretty bad in integration and scaling. Phaser gave high TFZ scores for 2 molecules in the asu (see below). Density for a cholesterol like ligand shows up even though not present in the search model. MolRep Self rotation shows rotational symmetry. https://www.dropbox.com/s/2zsajl5o091k50r/CYP142A2-032814_21_rf%20copy.pdf The 2 molecules in the ASU are related by almost a 2 fold rotation: Rotation matrix for chain A to chain B: new_ncs_group rota_matrix 1.0000 0.0000 0.0000 rota_matrix 0.0000 1.0000 0.0000 rota_matrix 0.0000 0.0000 1.0000 tran_orth 0.0000 0.0000 0.0000 center_orth 15.2016 0.5245 33.7070 rota_matrix -0.9860 -0.1636 -0.0309 rota_matrix -0.1659 0.9511 0.2605 rota_matrix -0.0132 0.2620 -0.9650 tran_orth 34.3310 -24.0033 107.0457 center_orth 15.7607 7.2426 77.7512 RMSD, B onto A = 0.0007 after phaser RMSD, B onto A = 0.347 after one round of refinement in phenix Refinement using aniostropically corrected data (ucla web server: Services.mbi.ucla.edu/anisoscale) did not improve the Rfree in refinement. Statistics are listed below: UNIT CELL: 51.487 88.923 89.592 90 97.15 90 P21 RESOLUTION NUMBER OF REFLECTIONS COMPLETENESS R-FACTOR R-FACTOR COMPARED I/SIGMA R-meas CC(1/2) Anomal SigAno Nano LIMIT OBSERVED UNIQUE POSSIBLE OF DATA observed expected Corr 5.99 8280 1927 2087 92.3% 3.1% 3.3% 8246 35.09 3.5% 99.8* 20* 0.909 1296 4.30 14606 3401 3487 97.5% 3.3% 3.5% 14580 33.37 3.8% 99.9* 11* 0.843 2273 3.53 17961 4244 4445 95.5% 3.8% 3.9% 17944 31.11 4.4% 99.8* -2 0.789 2721 3.06 21954 5068 5221 97.1% 4.9% 5.1% 21933 24.81 5.6% 99.7* -2 0.780 3455 2.74 25741 5830 5933 98.3% 7.6% 7.6% 25713 18.88 8.6% 99.5* -2 0.782 4165 2.51 27859 6311 6483 97.3% 10.8% 10.8% 27824 14.06 12.3% 99.1* -2 0.774 4385 2.32 31336 6979 7084 98.5% 14.9% 15.3% 31296 10.49 16.8% 98.5* -4 0.748 5095 2.17 32396 7347 7567 97.1% 22.3% 22.7% 32341 7.46 25.4% 97.3* -7 0.728 5055 2.05 32254 7339 8047 91.2% 33.1% 33.5% 32075 5.06 37.5% 94.8* -6 0.724 5155 total 212387 48446 50354 96.2% 7.8% 7.9% 211952 16.57 8.8% 99.7* -3 0.768 33600 Processing with mosflm or HKL2000 managed to index but failed pretty bad in integration and scaling. Phaser: SOLU SET RFZ=27.5 TFZ=24.2 PAK=0 LLG=1711 RF++ TFZ=64.6 PAK=0 LLG=3610 LLG=4865