Hi Dimitris, First, thank you kindly for your wonderful reply - there is a lot of great information to parse through! I will have a look through GSAS and the provided mailing list as well.
To quickly add context, here are two images refined to my static structure (compared with experimental data): FM3m starting lattice - https://imgur.com/a/l1HJjLD R3m starting lattice - https://imgur.com/a/805dbOw It seems to me that the FM3m cubic lattice matches peak positions well (fewer reflections overall), but not so much the intensities. However, I think this can likely be refined more. The R3m refinement matches the diffraction well apart from the anomalous peak seen at a 2theta of ~0.85 (this is also the case with FM3m). This peak is not present in the 'excited' structure, which is peculiar, and seems to imply a change in symmetry. The key observable we see crystallographically is a deviation in an expected Debye-Waller-like behaviour, with anomalous peak shifts and intensity changes in reflections related to the (100) plane (e.g. the (200)/(400) reflections). I am thinking there is likely a change of symmetry occurring and hoping to eek it out using refinement. Best, Kamil ######################################################################## 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/
