The value of Rmerge(I) for reflections classified as 'observed' (see _reflns.observed_criterion) in a given shell. sum~i~(sum~j~|I~j~ - |) Rmerge(I) = -------------------------- sum~i~(sum~j~) I~j~ = the intensity of the jth observation of reflection i = the mean of the intensities of all observations of reflection i sum~i~ is taken over all reflections sum~j~ is taken over all observations of each reflection