On Wednesday, July 06, 2011 09:46:14 am Jacob Keller wrote:
> Dear Crystallographers,
> it seems to me that for clearly identifying/characterising anomalous
> scatterers for a solved structure, one could make a map using two
> datasets: one at the f" peak, one low energy remote.
That would be an approximation of the map it seems you actually want,
which would use the F_A amplitude terms from MAD analysis together
with your current model phases rather than the MAD phase estimates.
You could, for example, use CAD to merge the FA column output by
hkl2map with the phases from your current model.
> One would then
> use the signal both from the Bijvoet differences in the peak dataset
> plus the differences between the peak and low-energy datasets, which I
> think I have seen called "dispersive" differences. I guess this would
> be like a MAD map, but using pre-existing model phases--is there such
> an animal in the software, or would it even be helpful?
> Jacob Keller
Ethan A Merritt
Biomolecular Structure Center, K-428 Health Sciences Bldg
University of Washington, Seattle 98195-7742