Hi Narayan, there's nothing wrong with using data with I/sigmaI 2.5, Rsym 224.3 % for multiplicity 7.8 and completeness 98.2 %.
However, when you discarded frames you might have made the data worse - one should only reject data if they deviate systematically (e.g. from radiation damage). Weak data should not be rejected, and Rmerge is the wrong measure to judge about data quality. best, Kay On Wed, 18 Jul 2012 02:41:48 -0700, narayan viswam <[email protected]> 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 >
