Dear Ralf, Thank you very much for your answer. What we are actually trying to do is to refer to the tables of ITA (2006) 15.2.1.* where you have your space group & additional generators and voila! It's not the normalizers defined as a group but the group+normalizers defined as a new group.. 8) Here is yet another question-- I might be missing something obvious here so you got my apologies beforehand if it proves that I do: Take for instance SG #16, P222. I add the 3 translation operators x+1/2,y,z x,y+1/2,z x,y,z+1/2 plus the inversion: -x,-y,-z then I get SG #47, Pmmm with (2*b,2*c,2*a) -- but why not (2*a,2*b,2*c)? As I said, I'm highly suspecting that I'm missing something very very obvious but at this moment I'm baffled. With my best regards, Emre On 06/02/2011 07:32 AM, Ralf W. Grosse-Kunstleve wrote:
But we couldn't find a way to introduce "x,y,z+t" while we are "expand_smx"ing the space group with these operators.
The space_group class only supports finite groups (and only in settings that can be represented with integral rotation parts and rational translation parts). We have the class cctbx.sgtbx.search_symmetry, which multiplies the discrete origin shifts into the space group and keeps track of the continuous allowed origin shifts separately.
It would need new code to determine a full description of affine normalizers. (Are they considered space groups?)
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