Fwd: Re: [ccp4bb]: CNS composite_omit_map

[Sebastiano Pasqualato <sebastiano.pasqualato@lebs.cnrs-gif.fr>]

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 >>> I'm forwarding this mail I've got because
 >>> I thougth that would be worthy to know...


>Dear Sebastiano:
>
>I don't know the answers to your questions, but thought I'd
>point out that I posted a question about composite_omit to
>bionet.software.x-plor last week and it turned out that there
>were some problems in v0.9's & v1.0's composite_omit.inp, but
>v0.5's worked.  It was calculating the whole unit cell instead
>of the asu... and taking 3-4 days in my case!!!  The problem
>was in the .inp file, the code was fine.
>
>Someone from cns sent me email yesterday saying that the
>v1.0 input file on the web has been fixed.  But they didn't
>answer to the whole buliten board, so other people don't know
>to update their input files.
>
>If you've run composite omit v0.9 or 1.0, you might want
>to update your .inp files with the template that's on the
>web now.
>
>ahve fun
>diane
>
>
> > Dear all,
> > does anybody know exactly how CNS performs the calculation of its
> > composite_omit_map? All I could find in the CNS site is that:
> > "small regions of the model are systematically excluded. A small map is
> > made covering the omitted region. These small maps are accumulated and
> > written out as a continuous map covering the whole molecule (or the defined
> > region)."
> > ... not too much, isn't it??
> > How are the omit maps merged? Why is it unuseful (as stated in the input
> > file) to perform an Fo-Fc map, and a 2Fo-Fc map is recommended?
> > Thanks a lot,
> > Sebastiano
> >
> > Sebastiano Pasqualato
> > CNRS,
> > Laboratoire d'Enzymologie et Biochimie Structurales
> > 1, Avenue de la Terrasse
> > 91198 Gif-sur-Yvette Cedex FRANCE
> >
> > phone +33 (0)1.69.82.34.97
> > fax +33 (0)1.69.82.31.29
>
>--
>
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>
>diane h peapus, phd             dp72@cornell.edu
>Chemistry & Chemical Biology    +1-607-255-2174 (office)
>Cornell University              +1-607-255-2600 (graph room)
>Ithaca, NY 14853  USA           +1-607-255-1227 (fax)