Dear Marina, Just an observation from my side: if you are able to process your data in P622, there must be some 2-fold perpendicular to l, which would most likely be a non-crystallographic or a twinning axis. Is there a NCS 2-fold in the P321 data set you solved? If so, is it perpendicular to l? If not, there must be some twinning law that converts l into -l like -k,-h,-l
Also, careful analysis of your solved P321 structure could give some hints how the twinning might look like. Best, Herman -----Ursprüngliche Nachricht----- Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Marina Ley Gesendet: Donnerstag, 11. Juli 2019 12:50 An: CCP4BB@JISCMAIL.AC.UK Betreff: [EXTERNAL] [ccp4bb] twinning problems EXTERNAL : Real sender is owner-ccp...@jiscmail.ac.uk Hello everyone, I have the following problem: I have some really good data sets of about 1.6 A which could be processed in P 6 2 2 as well as in P 3 2 1. Intensity statistics tests indicate twinning (merohedral, twinning law: -h, -k, l, in P 3 2 1). But I did not find a good MR solution (R value around 60%) and when I try to refine it with the twin law I get really bad maps. However I could get one data set where the intensity statistics tests did not indicate twinning and I have already managed to solve the structure. SPACE_GROUP_NUMBER: 154 (P 3 (2) 2 1) UNIT_CELL_CONSTANTS: 57.56 57.56 159.98 90.000 90.000 120.000 number of molecules in asymmetric unit: 2 NCS: yes I could see a lot of amino acids in the electron density which were not in the search model. But it seems like most of my crystals are twinned. For a fragment screen which I would like to do I need to solve the twinned data sets, otherwise I have to search again for another crystallization condition. I don't know what to do next to solve the twinned data sets. Do you have any ideas or suggestions? Thanks in advance!!! Cheers, Marina Some information about the results from Xtriage: ----------Statistics independent of twin laws---------- <I^2>/<I>^2 : 1.586 (untwinned: 2.0, perfect twin: 1.5) <F>^2/<F^2> : 0.870 (untwinned: 0.785, perfect twin: 0.885) <|E^2-1|> : 0.564 (untwinned: 0.736, perfect twin: 0.541) <|L|> : 0.380 (untwinned: 0.500; perfect twin: 0.375) <L^2> : 0.208 (untwinned: 0.333; perfect twin: 0.200) Multivariate Z score L-test: 12.491 -- Marina Ley PhD Student, Research Group Professor Dr. Klebe Department of Pharmaceutical Chemistry Philipps-University Marburg Marbacher Weg 6, 35032 Marburg, Germany Phone: +49 6421 28 21392 E-Mail: marina....@pharmazie.uni-marburg.de https://urldefense.proofpoint.com/v2/url?u=http-3A__www.agklebe.de_&d=DwIBaQ&c=Dbf9zoswcQ-CRvvI7VX5j3HvibIuT3ZiarcKl5qtMPo&r=HK-CY_tL8CLLA93vdywyu3qI70R4H8oHzZyRHMQu1AQ&m=O01KIRRRZ9Krf6AS9sPy8bgILSyqYf592SmrmmH_H6I&s=OiBXd3CAqkfdaGH-2fS0EaH-dsY6ThKMKfqCYqiskZE&e= ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://urldefense.proofpoint.com/v2/url?u=https-3A__www.jiscmail.ac.uk_cgi-2Dbin_webadmin-3FSUBED1-3DCCP4BB-26A-3D1&d=DwIBaQ&c=Dbf9zoswcQ-CRvvI7VX5j3HvibIuT3ZiarcKl5qtMPo&r=HK-CY_tL8CLLA93vdywyu3qI70R4H8oHzZyRHMQu1AQ&m=O01KIRRRZ9Krf6AS9sPy8bgILSyqYf592SmrmmH_H6I&s=2E7Nx3y6NmEuT6FMtimCqLVG-RWhPaYfAMJwFMff_5c&e= ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
