Dear Kenneth, You should be able to find the information you are looking for in the logfiles of your dataprocessing at the scaling/merging step. E.g. in the logfiles of scala you will find "Total number of observations" and "Total number unique". I am sure Scalepack will produce similar output.
"Unique Reflections" is the number of measured unique reflections, not the number of theoretically possible unique reflections. As you mentioned, the number of measured unique reflections is usually less than the number of theoretically possible unique reflections. "Total reflections" is the total number of reflections measured, e.g. the reflections that passed your resolution cutoff and rejection criteria that may be hidden in the data processing software. This is the number of reflections you have before merging. Again, you do not need to look for references but in your logfiles. Best, Herman -----Ursprüngliche Nachricht----- Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Kenneth A. Satyshur Gesendet: Montag, 14. Juli 2014 17:12 An: CCP4BB@JISCMAIL.AC.UK Betreff: [ccp4bb] definitions of unique reflections There is some disagreement on terms used to deposit data. We need a definition and an algorithm for each definition. "Unique Reflections" My definition is all the possible reflections out to the high resolution reported not related by symmetry.  Where can I find this? The .mtz contains a list of all HKL calculated to the highest resolution. Usually, we are not able to measure all these diffraction spots due to limits of the detector, mechanical limits, crystal orientation, etc. 'Total reflections' The depositions server asks for total reflections. I assume it wants only those unique reflections we were able to collect, regardless of the sigma cut off. These are called 'observed'. The total we use in refinement will be a subset of the 'unique observed' that are cut on sigma. However, some crystallographers believe that we should not cut on sigma since some of the intensities may in fact be zero. Is this a question for both the Refmac and Phenix people? Please give us some guidance and maybe a reference or two that we can use. -- Kenneth A. Satyshur, M.S.,Ph.D. Senior Scientist University of Wisconsin Madison, Wisconsin 53706 608-215-5207
