On Wed, 2012-01-18 at 16:54 +0000, Paul Emsley wrote:
> On 18/01/12 10:47, Martyn Winn wrote:
> > This needs a 1-line fix in syminfo.lib file. In the spacegroup entry
> > (the second entry in the file), replace:
> >
> > symbol old  'P -1'
> >
> > with
> >
> > symbol old  'P 1-'
> >
> > This works for me at least. The syminfo.lib file can be found in:
> > .../coot-whatever/share/coot/syminfo.lib
> > or in:
> > .../ccp4-whatever/lib/data/syminfo.lib
> >
> > Yes, it is an mmdb issue, in that mmdb tries to match the spacegroup in
> > the CRYST1 card against the spacegroups in syminfo.lib (it checks
> > against "symbol xHM" and "symbol old" entries).
> >
> > There are apparently a handful of centrosymmetric entries in the PDB,
> > e.g. racemic mixtures of synthetic peptides. Actually, looking at the
> > spacegroups offered in the RCSB advanced search menu, "P 1-" is the only
> > case.
> >
> > Clearly, it is "only" a matter of convention whether you use "P -1" or
> > "P 1-" ....
> >
> 
> Thanks for looking into this Martyn.
> 
> So just to be completely clear, CCP4 is changing symbol old for P -1 in 
> symop.lib?
> 
> Paul.

I have changed it in syminfo.lib not symop.lib
That is what mmdb uses nowadays, and seems to be what you distribute.

I have CVS'd the change into the CCP4 repository, and I presume it will
appear in the next release.

Sue Roberts pointed out to me that CCDC write out "P -1". syminfo.lib
now has:

symbol xHM  'P -1'
symbol old  'P 1-'

which should cover both cases (mmdb checks against both xHM and old).

m

-- 
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*                                                                     *
*               Dr. Martyn Winn                                       *
*                                                                     *
*   STFC Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, U.K.   *
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