On Thu, 2010-04-08 at 23:26 +0100, Daniel Bonsor wrote: > both the Rfactor and Rfree get stuck at 30% and 36%
according to http://xray.bmc.uu.se/gerard/supmat/rfree2000/plotter.html these are higher than expected. With that said, R/Rfree should not be a fetish, and your model may be fine (i.e. as good as it could be given the data quality). Definitely re-check if you have the right space group. This may be painful, as dropping some symmetry will only increase the number of molecules in the asu, and you already have 8. Sometimes, however, R-factors stay "higher-than-expected" no matter what you do. It may be driven by noise in the low resolution domain, and you may consider re-processing the data more carefully. Or, if you have more crystals, just collect more data and/or try different cryoprotection. Cheers, Ed. -- Edwin Pozharski, PhD, Assistant Professor University of Maryland, Baltimore ---------------------------------------------- When the Way is forgotten duty and justice appear; Then knowledge and wisdom are born along with hypocrisy. When harmonious relationships dissolve then respect and devotion arise; When a nation falls to chaos then loyalty and patriotism are born. ------------------------------ / Lao Tse /
