Hi Graeme, How is your data binned?
I don't claim to be any statistician, but I seem to remember being told by such an individual that you need a decent number of reflections to be able to calculate a accurate/reliable second moment - and if, in your low-res bins, you have relatively few reflections, your values of second moment of Z can start to vary wildly. HTH, Dave On 01/06/07, Winter, G (Graeme) <[EMAIL PROTECTED]> wrote:
Hi Folks, I was wondering if there is a document somewhere explaining some of the more interesting things which can be interpreted from the plot of second moment of Z = I'/<I'> anywhere? I've looked around and I can't find much beyond the things pertaining to twinning, where it will have the magical values of 2.0 or 1.5. What about if it is say 2.0 around the low resolution regions but gets much bigger? Looking at the truncate source code there is a note to the effect that the second moments may be greater than two in when you have pseudotranslational symmetry. In this case, however, I would expect that the effect would be uniform across the resolution ranges… any thoughts? Any pointers would be greatly appreciated. Thanks, Graeme
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