Re: [ccp4bb]: refine using merged MAD data of all 3 wavelength?

[<yxiong@chemistry.ohio-state.edu>]

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CNS has an option to use the data with Friedel pairs unmerged to refine the 
f' and f'' of the anomalous scatterers. This acctually helped the refinement 
in the case I mentioned. Again I am not sure how valiad this is for a merged 
3-wavelength data.

Yong

Phraenquex VD <loretta@scripps.edu> said: 

> I'd say this is a very good idea:  if your crystal did not decay, and if
> you don't have a higher-resolution (native) dataset you'd prefer to use,
> merging all datasets for super-high redundancy can only improve matters.
> Not sure about the averaging f'/f" - do any programs actually use this?
> 
> Cheers
> Phraenquex  
> 
> 
> On Wed, 11 Oct 2000, Yong Xiong wrote:
> 
> > Date: Wed, 11 Oct 2000 17:32:36 -0400 (EDT)
> > From: Yong Xiong <yxiong@chemistry.ohio-state.edu>
> > To: ccp4bb@dl.ac.uk
> > Subject: [ccp4bb]: refine using merged MAD data of all 3 wavelength?
> > 
> > ***  For details on how to be removed from this list visit the  ***
> > ***    CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html    ***
> > 
> > As title, I would like to know whether any one tried to use all 3 
wavelength data merged/scaled
> > together for the refinement. I tried this on one structure and it 
appeared to improve the
> > refinement. I am not sure the theoretical/practical soundness of doing 
this. If the
> > crystal is stable, it should give a lot more redudency to the data and 
help the high resolution
> > bins. The anomalous/dispersion signals would be messed up but mostly they 
are not used in
> > refinement any way. We could even give an average f' and f" for the 
merged data, or could we? Any
> > comments?
> > 
> 
> 



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