Re: [ccp4bb]: What is the CCP4 (refmac5) equivalent of an omit map?

[Ethan Merritt <merritt@u.washington.edu>]

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On Friday 25 January 2002 11:16, Bernhard Rupp wrote:
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> In pdb are a number of structures, where refmac TLS was used, (converted
> to Uij s) and these structures show *extraordinarily* low freeR and R for
> the resolution. So I wonder to what degree your higher rfactors of the CNS
> model reflect just that, and also, to what degree those low TLS rfactors
> reflect a truely better model?

Furthermore I have just run into a case where the refmac TLS model 
has lower R and Rfree than full anisotropic refinement.  I found this
hard to believer, so I replicated the aniso refinement in shelx.
I'm still scratching my head over this one, but for the moment it seems
to be real.  The resolution is distinctly margical (1.5A) for full aniso,
but I would have expected that if the refinement went bad I'd get a 
lower R but higher Rfree;  that's not what happens.

(watch for poster at the ACA meeting :-)


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center Box 357742
University of Washington, Seattle, WA 98195
phone: (206)543-1421
FAX:   (206)685-7002