On Saturday, 19 April 2014 02:52:38 PM Zbyszek Otwinowski wrote:
> Why not improve "effective resolution" to include consideration of solvent
> content? Due to constant packing density of proteins, it would become a
> synonim (by appropriate transformation) to number of observations per
> modelled atom.
Following that line of thought, perhaps reporting the observation/parameter
ratio would provide a more informative number than "resolution".
Of course that leads to a morass of argumentation about whether to modify
it by the number and class of restraints used during refinement.
Ethan
>
> Zbyszek Otwinowski
>
>
> > Dear Dale, dear Kay,
> >
> > last year, we discussed this kind of problems (Urzhumtseva et al., 2013,
> > Acta Cryst., D69, 1921-1934).
> > Our approach does not tell you where to cut your data and which
> > reflections to accept / reject but as soon as you have your set of
> > reflections, you calculate very formally and very strictly the "effective
> > resolution" of ANY diffraction data set, with ANY completeness, with ANY
> > composition of measured / missed reflections. For a complete data set,
> > d_effective coincides with the d_high value but is different for
> > incomplete data sets. The article contains a number of examples.
> >
> > With this approach, the discussion of the completeness of the
> > highest-resolution shell becomes irrelevant; one can simply cite the
> > "effective resolution". I hope this can help.
> >
> > With best regards,
> >
> > Sacha Urzhumtsev
> >
> > ________________________________________
> > De : CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] de la part de Dale
> > Tronrud [de...@daletronrud.com]
> > Envoyé : samedi 19 avril 2014 03:20
> > À : CCP4BB@JISCMAIL.AC.UK
> > Objet : Re: [ccp4bb] crystallographic confusion
> >
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> >
> >
> > I see no problem with saying that the model was refined against every
> > spot on the detector that the data reduction program said was observed
> > (and I realize there is argument about this) but declare that the
> > "resolution of the model" is a number based on the traditional criteria.
> >
> >
> > Dale Tronrud
>
>
> Zbyszek Otwinowski
> UT Southwestern Medical Center at Dallas
> 5323 Harry Hines Blvd.
> Dallas, TX 75390-8816
> Tel. 214-645-6385
> Fax. 214-645-6353
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