[ccp4bb] MTZ cell troubles after sortmtz reindexing from P321 to C2

Protein crystallography Programs for crystallography X-ray detectors
Basic tutorials:
Protein Peptide

CCP4bb navigation

CCP4bb <-- 2008 <-- March 2008 <-- 07 March 2008

Previous message:
Subject: Re: isopropanol as a precipitant
From: Patrick Shaw Stewart Patrick {- at -} DOUGLAS {- dot -} CO {- dot -} UK
Date: 2008-03-07

Next message:
Subject: Re: Merging CCP4i projects from two computers
From: Edward Berry eaberry {- at -} LBL {- dot -} GOV
Date: 2008-03-07

Subject: MTZ cell troubles after sortmtz reindexing from P321 to C2
From: Pietro Roversi pietro {- dot -} roversi {- at -} PATH {- dot -} OX {- dot -} AC {- dot -} UK
Date: 2008-03-07

Dear all,
after much sweat and grief I managed to index my data in
P321 but looking at the symmetry I think they might be C2: reindexing
from P321 to C2 with the 2h+k, k, l operator in sortmtz produces the
right cell (and yes I did tick the "Reduce reflexions to the asymmetric
unit" button so that noreduce is not among the sortmtz keywords):

P321 209.3168 209.3168 40.6822 90.0000 90.0000 120.0000
C2 362.5473 209.3168 40.6822 90.0000 90.0000 90.0000

But: scala then decides that the asymmetric unit is not the right one
and it mysteriously changes cell parameters (which I think points to a
bug in the sortmtz process of reindexing):

Reciprocal space symmetry:
Space group: "C 1 2 1" Point group: "PG2" Laue group: "2/m"
Reference asymmetric unit: "k>=0 and (l>0 or (l=0 and h>=0))"
(change of basis may be applied)

and I end up with this C2 cell in the mtz output from scala:

285.9320 285.9320 40.6824 90.0000 90.0000 90.0000

I have tried OUTPUT ORIGINAL ans some such in scala but to no avail.

Now please don't all tell me to go back and reindex-reintegrate these
images - although I might have to do it to get the best out of these
data once I am convinced they are monoclinic.

Rather, I would appreciate suggestions on what program to feed the
multirecord mtz to sort its asymmetric unit in C2 so that scala does not
play tricks on me; or what keyword to feed scala to keep reflexions in
the current asymmetric unit (and use cad or sftools afterwards on the
scaled/merged file)

Thanks

Pietro

--
Pietro Roversi
Sir William Dunn School of Pathology, Oxford University
South Parks Road, Oxford OX1 3ER, England UK
Tel. 0044-1865-275385

CCP4bb navigation

CCP4bb <-- 2008 <-- March 2008 <-- 07 March 2008

Previous message:
Subject: Re: isopropanol as a precipitant
From: Patrick Shaw Stewart Patrick {- at -} DOUGLAS {- dot -} CO {- dot -} UK
Date: 2008-03-07

Next message:
Subject: Re: Merging CCP4i projects from two computers
From: Edward Berry eaberry {- at -} LBL {- dot -} GOV
Date: 2008-03-07