Well, CCP4 programs using the core libraries should ignore the
spacegroup symbol and use the operators instead, which bypasses the
whole problem. I would advise anyone using the CCP4 libraries in their
own programs to do the same.
That works for mtz and map, but not for pdb files of course.
Kevin
Nat Echols wrote:
On Thu, Sep 2, 2010 at 5:31 AM, <herman.schreu...@sanofi-aventis.com
<mailto:herman.schreu...@sanofi-aventis.com>> wrote:
The other question is: why does phaser write 'R 3 :H' in the mtz? When
the problem with the P21221 space group first popped up last year, Randy
told me that space group numbers like 2018 are non-standard, and that
space group 18 with the name P21221 was the way to go. This is fair
enough, but 'R 3 :H' is neither PDB nor ccp4 standard and I did not find
it in the international tables. Is it maybe a phenix standard?
No, it pre-dates Phenix - it's the " extended Hermann Mauguin symbol",
whatever that means:
http://www.ccp4.ac.uk/html/symmetry.html
I don't know why it's used preferentially in Phenix, but in theory it's
supported by CCP4 programs, except those which are still using the older
symmetry information. syminfo.lib has the correct information (space
group number 146), symop.lib does not. As previously noted the last
time this discussion came up (December, if memory serves), Coot also
uses this notation:
http://www.biop.ox.ac.uk/coot/doc/coot/Reading-coordinates.html
-Nat
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