narayan viswam wrote:
Hello CCP4ers, In my data, the highest reolution shell 2.8-3.0 A has I/sigmaI 2.5 & Rsym 224.3 % for multiplicity 7.8 and completeness 98.2 %. I solved the structure by MAD & refined it to Rfree 27.3 %. Ths crystal belongs to P622 space group and it is not twinned. The water content is 68%. I loweredthe multiplicity to 4.1 by excluding few images but still the Rsym is > 200 % and I/sigmaI > 2.0. My rudimentary crystallography knowledge makes me believe it's quite Ok to use data upto 2.8 A and report the statistics. Could I request people's views. Thanks very much. Narayan
After refinement, what is R-free in the last shell? If it is significantly better than random, say around .4 or less, that could be taken as evidence that there is data in the last shell. Also check the error model- Rsym >2 sort of implies the error is greater than the signal, so I/sigI 2 seems surprising. eab
