Dear all, Instruction says: Anomalous groups refines the anomalous coefficients f' and f'' for anomalously scattering atoms such as Se or heavy metals; it is only appropriate if you have anomalous data (I+/I- or F+/F-). How do I indicate which atoms to be considered? Thank you for your help. Happy New Year. Pawel ____________________ Dr. Pawel Grochulski, D.Sc. Canadian Macromolecular Crystallography Facility (cmcf.lightsource.cahttp://cmcf.lightsource.ca/), Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada. Phone: +1 (306) 657-3538, Fax: +1 (306) 657-3535. Adjunct Professor of Pharmacy, College of Pharmacy and Nutrition, University of Saskatchewan (www.grochulski.comhttp://www.grochulski.com/) __________________________________________________________________________________________