[phenixbb] How the sharpening were performed in PHENIX.
pafonine at lbl.gov
Tue Jul 19 16:54:27 PDT 2011
> I was trying to do a B-factor sharpening using phenix GUI CreatMaps
> utilities. The output for the sharpened maps contains 2FOFCWT and
> PHI2FOFCWT columes, so I think they are sigmaA weighted 2Fo-Fc maps.
there is no need to guess. If you look at the "Map type" filed it will
tell you which map you computed. Looking right now: "Map type" says
"2mFo-DFc", and the corresponding labels are 2FOFCWT, PH2FOFCWT.
So the answer: yes, what you get is the maximum-likelihood weighted map.
> from Brunger's paper, the sharpening coefficients seems directly applied
> on Fo, and I wonder what happened before we get the 2mFoDFc maps. Or, the
> sharpening coefficients have been applied to the 2mFoDFc maps?
I do not remember what's in that paper, my vague recollection is that
the exp(B*s**2) is applied to F=map_coefficients. Anyway, in PHENIX the
exp B-sharpening applied to the map coefficients (not to Fobs). You have
two options here: provide your own B-factor to be used for sharpening or
let PHENIX determine it automatically.
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