Dear Crystallographers,
I've long heard second-hand about the need for favorable observation-to-parameter ratios, but have never really delved into the original literature. Does anyone know of a good source explaining and/or demonstrating this requirement, and perhaps showing how aspects of crystallography per se color the relationship? Ideally this would be an original source (I've found this seems to be the only way to really get to the bottom of things, and is much more efficient than reading digests or reviews, although the "James" might be an exception.)
For a crystallographic example, some observations are I/sig of 2, some 50, and it does not seem right to weigh them equally for these purposes. More specifically, I have a case of a truncated dataset which is cut off at 1.7 Ang due to the detector, but I think the dataset would have gone to 1.4-1.5 with a different setup. Does having a few thousand more measurements at I/sig = ~2 make that much of a difference? How should one think about this?
Thanks,
Jacob Keller
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Jacob Pearson Keller, PhD
Looger Lab/HHMI Janelia Research Campus
19700 Helix Dr, Ashburn, VA 20147
email: [log in to unmask]
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