Re: Detwinning Data in R3 space group. (fwd)

["Dr N. Chandra" <nc42@leicester.ac.uk>]

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Dear Louisa Smith,
 
You can use DETWIN program of Leslie which is now a part of the package of 
CCP4 to detwin your data. OR  you can use SHELXL97 program which
takes care of merohedral twinning (make sure that your data are
merohedrally twinned before detwinning because there are different kinds
of twinning). I have a program which calculates the twin
volume fraction and detwines data (UNMERGED so that MAD data can be
treated for partial merohedral twinning) directly from SCALEPACK. I
am updating the program so that it can be used for all the space groups
But you can use either programs.
 
Probably the twin matrix in your case should be: 
 
( 0 1 0  1 0 0  0 0 -1)

Note that I solved a structure in R3 with the twinned data. If you require
any further help, you can contact me (nc42@le.ac.uk) or Peter Moody
(pcem1@le.ac.uk)
 
Neverthless, confirm your twin operation.
 
 
Good luck
 
Naveen Chandra
 

______________________________________________________________________________


  Hi There,

> > I have data for some crystals that are merohedrally twinned (about 30%).
> > The crystals are in spacegroup R3, with the twin fraction along the a-b
> > plane. Does anyone happen to have, or know of, a quick and easy program
> > that will detwin this data??
> > 
> > 
> > Thanks alot in advance
> > 
> > 
> > Louisa Smith
> > 
> > School of Biochemistry and Molecular Biology
> > University of Leeds
> > Leeds
> > LS2 9JT
> > UK
> > 
> > Tel: 0113 2331402
> > Fax: 0113 2331407
> > 
> > BMBLS@BMB.LEEDS.AC.UK
> > 
> >> >