Usually this means that you have relatively high multiplicity, which give-or-take improves the I/sig(I) by sqrt(m) where m is the multiplicity, but also increases the Rmerge.
For any given narrow shell of reflections, Rmerge ~ 0.8 / unmerged(I/sig(I)) merged(I/sig(I)) ~ sqrt(m) * unmerged(I/sig(I)) So it is perfectly possible to have unmerged I/sig(I) of 0.8 which will give you an Rmerge of around 1.0, and have I/sig(I) (merged) around 3, by having multiplciity 14 or so. I suggest that this is the case: if it is much lower than this there is something odd going on. For the merged I/sig(I) Rpim is much more instructive. I'd love it if people reported merged and unmerged I/sig(I), Rmerge, Rmeas, Rpim, CC1/2, ... as each of these tells something different. Best wishes, Graeme Possibly useful papers: http://www.nature.com/nsmb/journal/v4/n4/abs/nsb0497-269.html http://scripts.iucr.org/cgi-bin/paper?he0191 http://scripts.iucr.org/cgi-bin/paper?he0268 On 19 November 2013 06:43, Shanti Pal Gangwar <[email protected]> wrote: > Dear All > > > Can anyone explain the meaning and relevance of data when the Rmerge is > 100% in high resolution shell and I/sig(I) is 3. > > > > Thanks > > > > -- > ******************** > regards > Shanti Pal Gangwar > School of Life Sciences > Jawaharlal Nehru University > New Delhi-110067 > India > Email:[email protected] > > >
