Re: [ccp4bb] Merging datasets

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

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From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-08

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Subject: Re: Merging datasets
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-08

There might be many reasons..

Do you have a spacegroup with alternate indexing? If so the two crystals
may not be using the same convention.
See $CHTML/reindexing.html for more details.

Or is one data set a high resolution pass and one a low resolution pass?
Sometimes then there are saturated spots which mess up the scaling..

I usually merge both sets independently first - cad them together and
run SCALEIT to check the degree of agreement.

SCALEIT gives a useful list of outliers and you might be able to
pinpoint the problem from that.

Kianoush Sadre-Bazzaz wrote:
> Dear CCP4,
>
> I have a couple of datasets native and heavy-atom-derivatized. The
> spacegroup and cell dimensions of all are the same (or very
> similar). For some reason I cannot merge any of the datasets
> together. If for example I rescale one native dataset by itself, my
> Rmerge is about 10%, but when I add 50 images (or so) of another,
> supposedly isomorphous crystal, my Rmerge goes up to 20%.
>
> I was wondering if anyone has encountered a similar problem or can
> offer any suggestions. Thanks so much,
> Kianoush
>
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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: CCP4 mailing list
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-08

Next message:
Subject: Re: CCP4 mailing list
From: Michele Lunelli efunit {- at -} YAHOO {- dot -} IT
Date: 2007-08-08