Hi Gihan, I guess your XFEL data set consists of data of hundreds of micro-crystals with only partials?
The first thing I would do is to ask the beamline people for the best strategy. Since they (should) have tested the beamline, they are probably the best people to ask. Next, in the early stage I would not worry about the point group and space group but try to process all images in P1. Depending of the crystal orientation, only two cell axis might be well defined in the individual images. From all these individual images, it should be possible to distill the cell lengths and angles. Using this parameters, I would again process all images and compile a P1 data set. Then, I would analyze the resulting data set with pointless or aimless or similar programs to try to find out what the point group and space group COULD be. Good luck! Herman -----Ursprüngliche Nachricht----- Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Gihan Ketawala Gesendet: Donnerstag, 19. April 2018 03:13 An: CCP4BB@JISCMAIL.AC.UK Betreff: [EXTERNAL] [ccp4bb] determining the point group and the space group Hi, my question is; how should one determine a point group and the space group of an unknown crystal? I have a protein crystal with know unit-cell parameters. (these are XFEL data so indexing wouldn't give the point and space groups). I checked the PDB, but no luck the PDB structures have the different space group assigned, no definitive answer hopefully, somebody can point me in the right direction Best, Gihan
