I think Gerard has probably hit the jackpot. The data was sent to me by a student and here is a bit of the header:
* OPENED INPUT MTZ FILE Logical Name: HKLIN Filename: 105456487_mx32736v69_xGSTPBBRETLGHA00BA54831_scaled_unmerged.mtz * Title: From XDS file SCALED_SAD_SWEEP1.HKL, XDS run on 19-Sep-2024 from image* I will check what version of XDS was used then but I suspect it is the one recently updated! The structure solves quite well in P212121 and refines to ~ 23% Not good data - not a perfect structure but probably NOT twinned. Can someone warn the community about this? Eleanor On Tue, 8 Oct 2024 at 17:38, Ian Tickle <ianj...@gmail.com> wrote: > PS you'll find a link to a description of all the twinning tests it runs > on the server home page. > > I. > > > On Tue, Oct 8, 2024 at 4:20 PM Ian Tickle <ianj...@gmail.com> wrote: > >> >> Dear Eleanor >> >> Try submitting it to the STARANISO server? That does a whole slew of >> twinning tests (so you can take your pick from sometimes totally different >> twin fractions from the various tests!). Also it gives you the twin >> fraction rather than having you understand how to use the tests! But I >> agree that the L test is one of the best, and the server uses a variant of >> it which gives more accurate estimates of the twin fraction. >> >> Cheers >> >> -- Ian >> >> >> On Tue, Oct 8, 2024 at 4:01 PM Eleanor Dodson < >> 0000176a9d5ebad7-dmarc-requ...@jiscmail.ac.uk> wrote: >> >>> I have always had great faith in the L test and other statistics to >>> detect twinning.. >>> But now I have a puzzling data set. >>> Seems to be orthorhombic with a, b and c all different >>> One molecule/asymm unit and no NC translation.. >>> BUT clear indication of twinning given by second moments, etc.. >>> >>> I have seen this before when the spacegroup was actually monoclinic and >>> the pointless analysis of the two fold axes along a b or c showed one was >>> better than the other two and in fact the crystal proved not to be twinned >>> when the data was processed as monoclinic.. >>> >>> But in this case no amount of reprocessing gets rid of the twin >>> indicator .. >>> Does anyone have any suggestions of why this might be? >>> ( The data quality isnt great - 2.5A but the Rmerges are reasonable..) >>> Eleanor >>> >>> >>> ------------------------------ >>> >>> To unsubscribe from the CCP4BB list, click the following link: >>> https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 >>> >> ######################################################################## 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/
