On Tue, Oct 11, 2011 at 10:34 AM, Ed Pozharski <epozh...@umaryland.edu>wrote: > > "expected value of unknown structure factors for missing reflections are > better approximated using DFc than with 0 values." >
better, but not always. What about say 80% or so complete dataset? Filling in 20% of Fcalc (or DFcalc or bin-averaged <Fobs> or else - it doesn't matter, since the phase will dominate anyway) will highly bias the map towards the model. Clearly there are cases where filling in a few missing reflections significantly improves map interpretability without introducing any bias. > As for phenix, I am not entirely sure - > it seems that phenix.refine does too (fill_missing_f_obs= False), but if > you use the GUI then the fill in option is turned on. > phenix.refine always outputs two 2mFo-DFc maps: one is computed using the original set of Fobs, and the other one is computed using set of Fobs where missing reflections filled in with DFc calculated using well determined atoms only. By default, Coot will open the "filled" one. Pavel
