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.
