Hi Jacob, >>The systematic absences in the hkl file pointed to P212121 being the space group, which is what it was processed in. If the data were processed in this space group (Laue class), the analysis of the systematic absence won't tell anything else. Probably, it would be more useful to process data in P1 and then rerun space-group determination. It would be useful to look at some statistics in the processed data, particularly the R(int) and the R(sigma) values. Since the R(int) is a measure of reproducibility, high values can mean the Laue group is wrong, poor/no absorption corrections, crystal twinning or disorder etc. R(sigma) relates to the signal-to-noise ratio of the data, and the R1 should stay close to R(sigma) in a rough estimate. Also, If R(int) is much greater than R(sigma) (say, 2 - 3 times), that usually indicates a problem in data. If you have access to diffraction images, look at several of them for possible disorder or twinning. If you have got good data, then you can look for further problems in the model.
HTH, Rangana On Thu, Jun 3, 2021 at 8:45 PM Jacob Summers < 000060a137e4bf3a-dmarc-requ...@jiscmail.ac.uk> wrote: > The systematic absences in the hkl file pointed to P212121 being the space > group, which is what it was processed in. As for the peaks, the highest > peaks are 3.92 at 2.72 A from an oxygen (Q1), 3.67 at 2.74 A from an oxygen > (Q2), and 2.68 at 2.75 A from an oxygen (Q3). Q1 and Q3 seem to be about > 2.82 A from each other and both appear to coordinate in the center of the > cyclic molecule. Filling these densities decreases the R1 value, but the > atoms do not refine well. I have been using ShelXle for refinements and > visualization but am new to the software and small molecule refinement. > > Thanks, > Jacob > > ######################################################################## > > 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/
