[phenixbb] sulfate on a 2 fold axis

Hi, I am finishing to refine a structure using Phenix. A sulfate ion is located on a 2 fold axis. When I refine the structure with Refmac, the geometry of the ion is well conserved, while when I use Phenix the geometry is destroyed and the sulfate ion is like a cross!! Any idea to keep the good geometry of this ion in Phenix during the refinement? Thanks in advance, David -- David Cobessi Institut de Biologie Structurale 41, Rue Jules Horowitz 38027 Grenoble Cedex-1, France Tel:33(0)438789613 33(0)608164340 Fax:33(0)438785122