Dear Crystallographers, I hate to broach this subject again due to its wildly controversial nature, but I was wondering whether there was any reference which systematically analyses resolution cutoffs as a function of I/sig, Rmerge, Rmeas, Rpim, etc. I strongly dislike Rmerge/Rcryst for determining cutoffs, for obvious reasons--and especially for datasets of higher multiplicity--but nevertheless it is a ubiquitously-reported statistic, and one therefore has to make an argument against using it. Hopefully this could be done by pointing to a definitive reference--or am I stuck with a convention versus the truth? Maybe the ACA or similar could make a public anti-Rmerge proclamation about it, to make it easier for us?
Also, more generally, it seems that the refinement programs are now better able to discount lousy high-res data, so why not leave the choice to those programs, and just give them all of the data to the edge of the detector, especially since our computational and data storage capacities are now completely sufficient for that? One could then use some other metric for the goodness of the structure, such as what bin crosses the Rfree = 40% mark or something. One could push this even further and, as has been mentioned on this list before, just give the refinement program all of the intensities of the voxels in the 3D dataset? Jacob -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program email: j-kell...@northwestern.edu *******************************************
