Re: [ccp4bb] Rfree continues to decrease while Rcrys is more or less static

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CCP4bb <-- 2007 <-- April 2007 <-- 23 April 2007

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From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
Date: 2007-04-23

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Subject: Re: Rfree continues to decrease while Rcrys is more or less static
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-04-23

This is unlikely to be the result of the method you used to solve the
structure.
It is probably due to you having some NCS related reflections in the
free set and some not.
First consider the direction of your 4 fold - could you have a higher
symmetry space group?
Eleanor

Vineet Gaur wrote:
> Hi all
>
> i m trying to solve a structure at 2.2A using MIR.
> i obtained phases using solve. density modification n model building
> was carried out using phenix. i m solving structure in p212121 space
> group, with 4 fold NCS. i got almost 80% model built using phenix,
> rest of the model was built using coot.
> Right now i am refining the structure at 2.2 Presently Rfree is 36.31%
> n Rcrys is 35.77%.
>
> Now whatever changes i made, Rfree continues to decrease while Rcryst
> is more or less stable.
>
> what could be the possible reasons for such a condition. it would be a
> great help if i can get few tips to overcome this problem.
>
> Thanx in advance
> Vineet Gaur
>

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CCP4bb <-- 2007 <-- April 2007 <-- 23 April 2007

Previous message:
Subject: truncate disregard - thx
From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
Date: 2007-04-23