In short: There may be crystallographic symmetry by disorder. If both the complexes are randomly set to both the positions, you may have indeed a symmetry center.
Joerg Am Mittwoch, den 05.11.2008, 15:56 +0800 schrieb [EMAIL PROTECTED]: > Dear all, > > Recently, I have refined the structure using powder data. In each > asymmetric unit of Pmc21, there are two chemically similar but > crystallographically different complexes. The center of these two > complexes is rougly around 0,0,0.75. Therefore, the true space group > may not be Pmc21. I am glad to know if there is a software to detect > symmetry and suggest probable space group. > > Thank you very much. > > best regards > stephen > >
