Hello all, I have just been experimenting with the refinement options for twinned data in phenix.refine (final 1.3 version), and I ran into a strange problem with the density fit validation function in Coot 0.4 and 0.5. When I "auto-open" the MTZ file with map coefficients produced by phenix.refine, I get a normal-looking map, but every single residue in the density fit plot is squarely in the red. When I open the 2Fo-Fc CNS format file also produced by phenix.refine, I get a map that looks identical to the first one, and when I validate the same model against the new map, I get the normal density fit pattern, with most residues in the green, and the occasional orange one. So it seems that the density fit calculation goes wrong for MTZ files from twinned refinement. Does anyone know what might be causing this? I can send the data files if required.
Cheers, -- Lieven Buts Ultrastructure Laboratory Vrije Universiteit Brussel