Hi,
you are right, the peak dataset corresponds to the highest f'' value.
However, this does not mean that f'' is null for the other
wavelengthes... you still have significant anomalous signal at the edge
and for the high energy remote wavelength... this will help your
phasing, so use it !
As Tim mentionned it : process all wavelength with anomalous switched on !
laurent
Le 30/05/2012 07:59, Qixu Cai a écrit :
> Thank you very much for your reply.
>
> In my own understanding,
>
> We collect the peak dataset, because of the large F'', and we can get
> strong anomalous signal.
>
> We collect the edge dataset, because of the large F', and combined with
> the remote dataset, we can use the method just like SIR to get some
> information about the phase.
>
> so I think for peak dataset, anomalous processing is necessary, and for
> edge and remote dataset, anomalous processing is not necessary.
>
> Is my understanding correct?
>
> Thank you very much for your help.
>
> Best wish,
>
> Qixu Cai
>
>
> 2012/5/29 Tim Gruene <[log in to unmask]
> <mailto:[log in to unmask]>>
>
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>
> Dear Qixu Cai,
>
> MAD phasing is based on the comparison of Bijvoet-pairs, i.e. I(hkl)
> with I(-h-k-l), both within one data set and between data sets.
> Therefore you might get better results if your integration program does
> not assume Friedel-pairs to have identical intensities, even though
> the difference is probably only marginal (integration programs do not
> merge data).
> So it is safest click on 'anomalous' for all data sets involved .
>
> Tim
>
> On 05/29/12 11:11, Qixu Cai wrote:
> > Dear all,
> >
> > Sorry for the question from MAD beginner.
> >
> > When we process the MAD datasets, including the peak-data,
> > edge-data and remote-data, which datasets need to be process with
> > anomalous?
> >
> > I know peak-data obviously need data processing with anomalous, but
> > what about edge-data and remote-data when we want to use MAD
> > method?
> >
> > Thank you very much!
> >
> > Best wishes,
> >
> > Qixu Cai
> >
>
> - --
> - --
> Dr Tim Gruene
> Institut fuer anorganische Chemie
> Tammannstr. 4
> D-37077 Goettingen
>
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--
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Laurent Maveyraud laurent.maveyraud AT ipbs DOT fr
Université Paul Sabatier / CNRS / I.P.B.S. UMR 5089
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Département Biologie Structurale et Biophysique
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