On 07/23/2015 05:30 AM, Keller, Jacob wrote:
> Not to harp on this too much, but I was helping a colleague today on an unrelated structure, and his dataset also showed negative CCanom's in all bins. I am now suspecting that there might be an actual bug in Aimless. Anyone else also seeing this?
>
> Jacob
>
>
A simple test is to input the data (e.g. a XDS_ASCII.HKL file) directly
into SHELXC (or via hkl2map) as for a SAD structure determination. Given
unmerged data this outputs CCAnom (called CC1/2) in resolution bins to
help one to decide where to cut the data for SAD phasing. If these
numbers are also negative, it wasn't a bug in AIMLESS. There does indeed
appear to be a tendancy for the SHELXC values to become slightly
negative at the high resolution end, i.e. when a value of zero would be
expected for pure noise, so maybe it is something more fundamental?!
George
--
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-33021 or -33068
Fax. +49-551-39-22582
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