[phenixbb] anomalous difference map

Phil Jeffrey pjeffrey at princeton.edu
Mon Sep 8 10:10:18 PDT 2014

In your first sentence your meaning of "difference map" is:
( F_obs - F_calc ), phases

For an anomalous difference map you're calculating:
( F(+) - F(-) ), phases-90

So you would still expect to see a peak in the anomalous difference map 
in the presence of the anomalous scatterer since you are not subtracting 
off its contribution to the scattering.

There probably would be (very) small differences in the phases dependent 
on whether you explicitly model the Br as an anomalous scatterer or not 
but I have never experimented to see if that makes a small impact on an 
anomalous difference map.

Phil Jeffrey

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