Re: [ccp4bb] short step

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

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Subject: Re: short step
From: Ethan Merritt merritt {- at -} U {- dot -} WASHINGTON {- dot -} EDU
Date: 2010-02-22

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Subject: Re: short step
From: "Edward A {- dot -} Berry" BerryE {- at -} UPSTATE {- dot -} EDU
Date: 2010-02-22

Subject: Re: short step
From: "Edward A {- dot -} Berry" BerryE {- at -} UPSTATE {- dot -} EDU
Date: 2010-02-22

Try grepping "crystal" your .x files (or whatever you called the
denzo output files). Also grep for "start".

By default denzo updates start-phi to the end
of the previous oscillation. Since 0,5 degree is within radius of
convergence, it re-refines crystal rotx to be compatible with this
assumption and the oscillation photograph, which means crystal rotx
will be moving backwards 0.5 degrees for each frame. Scalepack
in postrefinement sees this as a serious case of "slippage" and is
unable to postrefine a value of crystal rotx that is compatible with
all the frames.

It may be possible to turn of post-refinement with "POSTREFINE 0"
or some such.

Ed

Ed Pozharski wrote:
> I want to process bunch of frames with extremely short step - i.e. these
> are 0.5degree oscillations but crystal only rotates by 1 degree over
> 1000 frames (I would have kept it at the same orientation if Rigaku
> control software would allow zero step). Denzo can process the frames
> all right, but scalepack chokes on it saying "Floating Exception". I
> don't have much experience with mosflm, and it failed also.
>
> What I wonder is if this happens because both programs have some bug in
> these unusual conditions or there is something fundamental that prevents
> scaling such data?
>
> Cheers,
>
> Ed.
>

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

Previous message:
Subject: Re: short step
From: Ethan Merritt merritt {- at -} U {- dot -} WASHINGTON {- dot -} EDU
Date: 2010-02-22

Next message:
Subject: Re: short step
From: "Edward A {- dot -} Berry" BerryE {- at -} UPSTATE {- dot -} EDU
Date: 2010-02-22