With 7ucr the second dataset looks like the neutron one based on the number of '?' which is roughly as expected i.e. a very good crystal will give X-ray data to 1 Angstoms and neutron data to 2 Angstroms, more neutrons always being needed.
Best wishes, Jon Cooper. jon.b.coo...@protonmail.com Sent from Proton Mail Android -------- Original Message -------- On 24/02/2025 16:51, lucrezia catapano wrote: > Hi Doeke, > > I've encountered this issue quite often. > > The information should ideally be stored in the _diffrn.details flag, but > that's not always the case. Typically, the first array of reflections > corresponds to X-ray data and the second to neutron data, but this isn't > always reliable. There are cases where reflections are missing, or X-ray > reflections are mislabeled as neutron reflections and vice versa. > > For example, in the case of 5A93, the second array of reflections is named > data_r5a93Neutronsf, making it clear. However, in cases like 7UCR, it's not > as obvious. > > One way to determine which data array corresponds to which experiment is by > computing R-work using both X-ray and neutron scattering factors for each > data set. The incorrect set of scattering factors will result in > significantly higher R factors. While not ideal, this method is often the > only option when no other information is available. > > If you need to extract data arrays from a combined sf.cif file, you can > easily do so using gemmi: > > gemmi cif2mtz -B 2 file-sf.cif file.mtz > > Here, -B 2 specifies the second block in the file. > > Hope helps. > Lucrezia > > Lucrezia Catapano, PhD (she/her) > Postdoctoral Scientist, Murshudov Group > MRC Laboratory of Molecular Biology > Francis Crick Avenue, > Cambridge CB2 0QH, UK. > lucre...@mrc-lmb.cam.ac.uk > >> On 24 Feb 2025, at 16:17, Hekstra, Doeke Romke <doeke_heks...@harvard.edu> >> wrote: >> >> CAUTION:This email originated from outside of the LMB: >> .-owner-ccp...@jiscmail.ac.uk-. >> Do not click links or open attachments unless you recognize the sender and >> know the content is safe. >> If you think this is a phishing email, please forward it >> tophish...@mrc-lmb.cam.ac.uk >> >> -- >> >> Hi, >> >> Maybe a dumb question. When looking at some PDB entries based on joint X-ray >> and neutron refinement (e.g., 5A93, 7UCR), we’re confused about what is >> stored in the PDB-provided sfCIF files and/or how to tell the neutron >> diffraction from X-ray diffraction data. >> >> For example, for 5A93 I’d infer the sfCIF contains neutron data based on the >> resolution limit, but I don’t recognize any flag telling me more. >> >> Thank you, >> >> Doeke >> >> ===== >> >> Doeke Hekstra >> >> Associate Professor of Molecular & Cellular Biology, and of Applied Physics >> (SEAS), >> >> Director of Undergraduate Studies, Chemical and Physical Biology >> >> Center for Systems Biology, Harvard University >> >> 52 Oxford Street, NW311 >> >> Cambridge, MA 02138 >> >> Office: 617-496-4740 >> >> Admin: 617-495-5651 (Lin Song) >> >> --------------------------------------------------------------- >> >> 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 ######################################################################## 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/
