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Re: [ccp4bb]: Twinning/Merging
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> I disagree too, like Jim, and would not use Rmerge = 16% data for
> refinement, but rather transfer them into Trash...
That is a tad harsh, I think... especially if you don't have a choice, as
often happens. Jim didn't recommend trashing it either, I understand.
But if you have decay in each of the three crystals, and if you include a
lot of weak high resolution data, and if the three crystals are not
perfectly isomorphous, I think it adds up pretty quickly to 16%.
I should add that several (at least 3) of my SeMet experiments to date
worked spectacularly with a single peak wavelength (i.e. SAD) collected
from a single *frozen* crystal giving Rmerges of 10-13% (anomalous scaled
separately). The Rmerge may look shocking, but the proof is that the
anomalous signal was good enough to find lots and lots of selenium sites
and phase them too. Rmerge can be moulded by too many things (excluding
images, cutting resolution) for my comfort...
So I would certainly go along with this data, without worrying about
twinning unless you have stats to back it up, as recommended by a previous
mail (sorry, lost the name...)