Dear Patrick,
In addition to using hkl2map for SAD or SHARP for MAD, you could also use Phaser for SAD. The strength of Phaser in this situation is that it can make a good stab at working out which sites are which atom types. This changes the relative contribution of the anomalous scatterers to the imaginary and real scattering, which can improve the phases somewhat, and you can also tell the difference in good cases between the correct and incorrect hands. Assuming you can find the sites (which gets harder as the total number increases; an extra benefit of George’s good suggestion to go to a second wavelength where the Se atoms contribute much less is to simplify the substructure solution at that wavelength), having two kinds of atoms is actually an advantage.
Best wishes,
Randy Read
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Randy J. Read
Department of Haematology, University of Cambridge
Cambridge Institute for Medical Research Tel: +44 1223 336500
Wellcome Trust/MRC Building Fax: +44 1223 336827
Hills Road E-mail: [log in to unmask]
Cambridge CB2 0XY, U.K. www-structmed.cimr.cam.ac.uk
> On 5 Feb 2016, at 09:27, Patrick Pausch <[log in to unmask]> wrote:
>
> Hey folks,
>
> I’m currently working on a complex which shows increased crystallization and diffraction when co-crystallized with I3C (Iodine ligand). This is also true for the Se-methionine labeled variant. The iodine signal is usually accesible using CuKa radiation. I’m wondering if the anomalous signal of iodine (peak should be around 20 keV) will impede data processing after measuring selenium peak at synchrotron radiation source.
>
> Many thanks in advance!
>
> Patrick Pausch
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