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

[Bart Hazes <bhazes@ualberta.ca>]

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On Fri, 25 Jan 2002, Bernhard Rupp wrote:

> 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?

If you talk about coordinates then the TLS model doesn't need to be better
than without TLS, even if the R-factors are significantly lower. However, if
you consider B-factors as part of the model, and of course they are although
our normal display programs don't visualize them, then it appears that the TLS
models are better indeed, especially at medium and low resolution. The lower
R-free also suggests better Fcalc and thus a better map and possibly less
model bias. All of these could help to actually get better model coordinates
as well.

Bart

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