Hi Len, a possible theory: your crystals may be macroscopically twinned, i.e. consisting of single crystals attached to each other in the way that the twin operation describes. At your home source, you employ a rather big beam that hits more than one single crystal. So the data appear twinned. At the synchrotron however, the beam is way smaller, and may hit only a single crystal. Hence, untwinned data.
HTH, Kay On Mon, 25 Mar 2024 19:22:54 +0000, Thomas, Leonard M. <lmtho...@ou.edu> wrote: >Hello, > >I have run into a very odd situation. Upon collection and data processing on >a crystal on my home source all pointers seemed to show twinning. Was not >surprised since previous crystals under different but related conditions have >showed significant twinning though the cell dimensions were different but not >the resulting apparent space group. > >Now the odd thing, I sent the crystal to the synchrotron figuring I might be >able to get some data that might help figure out what is going on. Upon >processing of the synchrotron data, SSRL 9-2, magically no twining was >detected. A couple of other crystals of the same compound though not from the >same exact condition showed the twinning. I processed the data using HKL, >which I primarily on my home source data and XDS with similar results. > >In summary, the exact same crystal shows twinning on Cu home source and no >twinning at all at the synchrotron. > >Any ideas would be welcomed. > >Len > >Leonard Thomas, Ph.D. >Biomolecular Structure Core, Director >Oklahoma COBRE in Structural Biology >Price Family Foundation Institute of Structural Biology >University of Oklahoma >Department of Chemistry and Biochemistry >101 Stephenson Parkway >Norman, OK 73019-5251 >Office: (405)325-1126 >lmtho...@ou.edu<mailto:lmtho...@ou.edu> >http://www.ou.edu/structuralbiology/cobre-core-facilities/mcl > > >######################################################################## > >To unsubscribe from the CCP4BB list, click the following link: >https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > >This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing >list hosted by www.jiscmail.ac.uk, terms & conditions are available at >https://www.jiscmail.ac.uk/policyandsecurity/ > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
