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Re: [ccp4bb] refinment in lower space group vs. higher
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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999
Previous message:
Subject: refinment in lower space group vs. higher
From: Yu Jiang jyu {- at -} MAIL {- dot -} USTC {- dot -} EDU {- dot -} CN
Date: 2009-01-02		Next message:
Subject: Re: refinment in lower space group vs. higher
From: Anastassis Perrakis a {- dot -} perrakis {- at -} NKI {- dot -} NL
Date: 2009-01-03


Subject: Re: refinment in lower space group vs. higher
From: James Holton JMHolton {- at -} LBL {- dot -} GOV
Date: 2009-01-03

You should pick your free-R set in C2221 and then symmetry-expand it to
C2. Otherwise, every hkl in your "free" R set will have an NCS "mate"
in the working set, and using NCS restrains will completely invalidate
the free R analysis. That is, your free-R will be essentially equal to
the regular crystallographic R and it will be possible to take a
completely wrong MR solution and refine it to an "acceptable" free R,
and if you do that, we will all make fun of you.

-James Holton
MAD Scientist

Yu Jiang wrote:
>
> Dear all,
>
> I am now refining one structure in space group C2 with 2 molecules,
> however we find the data can be processed in C2221 with 1 molecule.
> The questions are:
>
> 1. Can I still use space group C2 instead of C2221, even if the two
> molecules almost have crystallographic symmetry? Should I provide any
> excuses?
>
> 2. Is there any indication or necessity to refine structures in lower
> space group instead of higher?
>
> Many thanks!
>
>
>

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999
Previous message:
Subject: refinment in lower space group vs. higher
From: Yu Jiang jyu {- at -} MAIL {- dot -} USTC {- dot -} EDU {- dot -} CN
Date: 2009-01-02		Next message:
Subject: Re: refinment in lower space group vs. higher
From: Anastassis Perrakis a {- dot -} perrakis {- at -} NKI {- dot -} NL
Date: 2009-01-03
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