On 03/11/2017 05:56 AM, Abhinav Prabhakar wrote:
Hello,
I have a question about the working of Artemis as a new user.
Artemis does not recognize the space group B11b. When importing a cif file of a crystal with this symmetry, it sends a prompt message that the space group symbol cannot be recognized. As a result, I changed it to P11b and it works. But would this change any crystal information (for eg. Degen, Reff values) significantly?
I am not a crystallography expert in any sense. When I wrote Artemis, I meticulously followed what I found in the fourth edition of the International Tables for Crystallography, Volume A. Every symbol defined in there is recognized by Artemis. (Well, I guess I should say that every symbol is /supposed to be/ recognized by Artemis. If one is missing, that's a bug and should be reported.) "B11b" is not a symbol that I found in my copy of ITC volume A. As Robert suggested, there may be a way to rotate group 9 so that "B11b" is an interpretable symbol in the abstract. But Artemis does not know how to do that. (Nor do I.) "P11b" is a setting for space group #7. If, as Robert suggests, your CIF file is for space group #9, then the answer to your last question is yes. It is plainly obvious that using a different space group will change the degeneracies and distances. Of course, you did not bother to include a copy of the CIF file in question to your original email, so it is not actually possible for Robert or I or anyone else to actually help you effectively. At the risk of sounding like an annoyingly broken record, everyone should take the time to ask a good question or write an actionable bug report: http://bruceravel.github.io/demeter/documents/SinglePage/help.html http://bruceravel.github.io/demeter/documents/SinglePage/bugs.html B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Building 743, Room 114 Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/