It would be possible with a bit of effort to apply such mixed restraints using SHELXL. However I'm not convinced that it is such a good idea, at the resolutions you are working at the geometry of the core regions will be primarily determined by the X-ray data anyway. Perhaps what we really need are B-value dependent distance and other restraints, so they are tighter if the B-values are higher and vice versa.
George Prof. George M. Sheldrick FRS Dept. Structural Chemistry, University of Goettingen, Tammannstr. 4, D37077 Goettingen, Germany Tel. +49-551-39-3021 or -3068 Fax. +49-551-39-22582 On Fri, 4 Jul 2008, Matthew BOWLER wrote: > Dear All, > I have looked everywhere for answers on this one with no luck... I have > several structures at reasonable resolution 1.7 to 1.1A. I have performed > unrestrained refinement on the model which is fine for the core protein and > ligands but the surface atoms start flying off a bit. So what I would like to > do is unrestrained refinement only on the ligands and leave the protein > restraints in place. I have a feeling that if I cannot do it in Refmac I > can in phenix but I cannot find anything out about that either. All help > greatly appreciated, yours, Matt. > > > -- > Matthew Bowler > Macromolecular Crystallography Group > European Synchrotron Radiation Facility > B.P. 220, 6 rue Jules Horowitz > F-38043 GRENOBLE CEDEX > FRANCE > ============================================================================= > Tel: +33 (0) 4.76.88.29.28 > Fax: +33 (0) 4.76.88.29.04 > > http://www.esrf.fr/UsersAndScience/Experiments/MX/About_our_beamlines/ID14-2/ > ============================================================================= > >
