I have data from a crystal with anisotropic diffraction. After scaling and merging using the webserver staraniso, I would like to refine using phenix refine. Could you tell me if phenixrefine will try to fill in the missing reflections that were removed in the staraniso procedure? If so, is there a a way to prevent this fill in? Following is the warning message for the Staraniso server: We are grateful to Andrew Leslie (MRC-LMB) for identifying a potentially undesirable 'feature' of CCP4/REFMAC (and possibly other refinement software), namely the 'fill-in' of unobserved data with *DF*calc which makes it effectively *incompatible* with the MTZ file output by STARANISO. Our advice is therefore to use *BUSTER http://www.globalphasing.com/buster* for refinement using the downloaded MTZ file, unless the user can find a way to disable that feature in the alternative software. In general, any treatment of STARANISO's output data that adds missing reflections out to the resolution limit may result in a very high proportion of unobserved data compared with data that have had a cut-off applied according to an isotropic criterion. Where missing reflections have been added in this way the user should take care to verify that any applications used to process the data subsequently can handle it correctly. Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491