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Re: [ccp4bb]: averaging with centred space groups
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Jan Abendroth wrote:
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> Dear crystallographers,
> I think to remember that non-crystallographic averaging during density
> modification is less powerful in (c)-centred space groups than in
> Is this true or complete nonsense?
> Could anyone give me a reference for this?
> I can't find it any longer.
> Thanks in advance and regards
I cant see why?
All averaging is less powerful if the operator does not sample different
points in reciprocal space; ie a pseudo translation is more or less
useless; a rotation which is parallel to a reciprocal crystallographic
axis is less useful than one in a totally general position.
In my experience NCS in monoclinic space groups is often about an axis
in the a-c plane so falls into this category. But that is simply
anecdotal - Kevin cowtan has done some exploration of this and discussed
it at the IUCr meeting in glasgow - Email him and ask if he published it
anywhere ( firstname.lastname@example.org)