-------- Original Message --------
Subject: Re: [ccp4bb] Space group and R/Rfree value
Date: Wed, 01 Dec 2010 09:44:06 -0700
From: Maia Cherney <[log in to unmask]>
To: Xiaopeng Hu <[log in to unmask]>
References:
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A dimer could be with a symmetry-related molecule in C2221, so there is
no need to have a dimer in the asym. unit.
Maia
Xiaopeng Hu wrote:
> Dear all,
>
> I am working on a data-set (2.3A) and the space group problem bothers me a lot.The space group of the data-set could be C2221 or P212121, since our protein functions as a dimer, and P212121 gives two molecular in the asym-uint, I think P212121 is more reasonable than C2221.However with C2221, I can refine the R/Rfree to 20/24 or lower, while with P212121 only to 26/30. Also Phenix points out that the crystal is probably a twin with P212121 but is OK with C2221.
>
> I am not a real crystallographer, perhaps this problem is stupid, any help will be appreciated!!
>
> Best wishes,
>
>
> Xiaopeng Hu
>
>
>
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