On Sat, 18 Jul 2015 15:14:45 +0100, Christopher Barnes <[log in to unmask]> wrote:
>Thank you all so far for the responses.
>
>As it pertains to indexing ambiguity, I'm not quite sure that this is the problem. Each wedge indexes with the same space group and unit cell, with dimensions easily falling within <0.5% of one another. In this case the crystal indexes as P212121.
In this spacegroup there is no indexing ambiguity, unless two of the cell axes are almost the same.
>
>I've seen this problem before but never to this severity. Usually with translation and processing in XDS the ISa will go from 25-30 to around 10-15. is it possible that because I am translating more frequently than usual (every 5-10 rames), this is causing a problem?
it should not matter how often you translate.
But it could still be a problem of radiation damage. Assuming the first 2 frames of each wedge are undamaged, and the last 2 frames are strongly damaged, then this might not influence ISa of that wedge, if there are no sym-related reflections between the first and last 2 frames. However as soon as you scale that wedge against other wedges, ISa may go down strongly, as the radiation damage becomes apparent from comparison, between wedges, of early and late frames.
HTH,
Kay
>
>Thanks again,
>
>Christopher
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