Dear Eleanor at al,
On Fri, Aug 20, 2010 at 05:20:05PM +0100, Eleanor Dodson wrote:
> There is quite a lot of background to these Qs in a variwty of text
> books, and something on this website.
> http://www.ccp4.ac.uk/dist/html/pxmaths/index.html
Nice page :-)
> When changing hand you need to consider whether this also involves a
> change of spacgroup; eg P32 instead of P31
It always does involve a change to the enantiomorph. One only ever
needs to check two solutions:
* if you started with your dataset in P31 you will have to check
(X,Y,Z) P31 and (-X,-Y,-Z) P32
and never: (-X,-Y,-Z) P31
* if you started with P32 just check
(X,Y,Z) P32 and (-X,-Y,-Z) P31
and never: (-X,-Y,-Z) P32
It helps to process data always in the same enantiomorph spacegroup
(since the extinction rules are identical): e.g. sticking with P61 and
P62 at the beginning and never go into P65 and P64 for a start (only
after phasing or MR points to that spacegroup).
Cheers
Clemens
--
***************************************************************
* Clemens Vonrhein, Ph.D. vonrhein AT GlobalPhasing DOT com
*
* Global Phasing Ltd.
* Sheraton House, Castle Park
* Cambridge CB3 0AX, UK
*--------------------------------------------------------------
* BUSTER Development Group (http://www.globalphasing.com)
***************************************************************
