Here is a start. It can imply you: 1. did not rotate through the complete unique angle to obtain all reflection intensities. 2. had the detector too close so did not record reflections which were outside the detector area. (extending the data resolution beyond the detector/experimental geometry) 3. had decay of your crystal and decided not to process the images after a set image number. (see 1 above) 4. had a shadow which ocluded the path from crystal to detector. (e.g., beam stop, beam stop holder, sample holder apendages, low temperature nozzle, etc.) 5. need an alternate/additional crystal orientation. 6. masked critical areas in your image (justified or unjustified). 7. had detector/beam/goniometer problems which precluded collecting parts or all of data. Reallize that if one image has a problem, any full or partial reflection intensity on that image is suspect and generally must be removed from the data set. If not collected elsewhere, it does not contribute to completeness. 8. You jsut have low symmetry crystals which need a lot of data. (see 1 and 5 above)\
Kris ________________________________ From: Rex Palmer <[email protected]> To: [email protected] Sent: Mon, May 10, 2010 8:42:22 AM Subject: [ccp4bb] Incomplete data If you measure a set of diffraction data without any particular restraints and it turns out, say at a given theta max, to be only 80% complete, what does this imply? Rex Palmer Birkbeck College
