[ccp4bb] Molecular replacement with merohedarlly twinned data

2009-09-11 Thread Pietro Roversi
Dear all,
when searching in Molecular Replacement
against say perfectly merohedrally twinned data (i.e. an alpha=0.5 twin)
do I understand it right that I should expect two sets of solutions
that are equivalent under the twin operator (bar xtal symmetry and/or
origin shifts)?

Thanks!

Ciao

Pietro
-- 
Pietro Roversi
EP Abraham Fellow in Biochemistry - Lincoln College - Oxford
Sir William Dunn School of Pathology, Oxford University
South Parks Road, Oxford OX1 3RE, England UK
Tel. 0044-1865-275385


Re: [ccp4bb] Molecular replacement with merohedarlly twinned data

2009-09-11 Thread Randy Read
Yes, but if the twin fraction deviates even slightly from 1/2, you may  
only get one solution from the search.  If you want, you can generate  
the other one and see how happy the program is.


Regards,

Randy

On 11 Sep 2009, at 15:12, Pietro Roversi wrote:


Dear all,
when searching in Molecular Replacement
against say perfectly merohedrally twinned data (i.e. an alpha=0.5  
twin)

do I understand it right that I should expect two sets of solutions
that are equivalent under the twin operator (bar xtal symmetry and/or
origin shifts)?

Thanks!

Ciao

Pietro
--
Pietro Roversi
EP Abraham Fellow in Biochemistry - Lincoln College - Oxford
Sir William Dunn School of Pathology, Oxford University
South Parks Road, Oxford OX1 3RE, England UK
Tel. 0044-1865-275385


--
Randy J. Read
Department of Haematology, University of Cambridge
Cambridge Institute for Medical Research  Tel: + 44 1223 336500
Wellcome Trust/MRC Building   Fax: + 44 1223 336827
Hills RoadE-mail: rj...@cam.ac.uk
Cambridge CB2 0XY, U.K.   www- 
structmed.cimr.cam.ac.uk