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Here's some notes for you wrt HKL2000 to the extent of my understanding. 'Partially recorded' reflections for an identical h,k,l, which can be spread over multiple images, are already 'combined' when you index and process the dataset in the Denzo component of HKL2000. During the subsequent scaling/reduction/merging step, two things happen: 1) multiple observations of a unique hkl are merged/averaged/combined AND 2) a reflection and its symmetry equivalents are merged as well. Since it appears that you have no prior knowledge of the space group for the data, unless you are confident of the suggested lattice type, simply use HKL2000 to index, process and scale data all the way through in P1. Even in P1, the Scalepack default is to combine multiple measurements of a unique hkl (step 1 above) but will still be "unmerged" wrt space group symmetry. But when you specify the 'NO MERGE' option in Scalepack, multiple measurements of a unique hkl will also not be merged. In your case, I don't think you need to use the 'NO MERGE' option in Scalepack.....Unless POINTLESS does not like redundant observations to be combined. I have never used POINTLESS but I doubt this is the case. HTH. Raji ---------Included Message---------- >*** For details on how to be removed from this list visit the *** >*** CCP4 home page http://www.ccp4.ac.uk *** > > > >Hi All: > >I am trying POINTLESS for detecting real space group using data processed >by HKL2000. Apparently, POINTLESS cries for unmerged data. I understand >using Mosflm might be the best in this case, but I am not familiar with >the program. > >So I did the following to rescue but not sure if it is the right thing. >1) Integrate (denzo) as P1 space group in HKL2000. 2) Scalepack in P1 >with keyword "no merge". 3) Using COMBAT in CCP4 to covert to mtz and >specify the input .sca file as "Scalepack file nomerged (no partials)". > >What I am more curious about, is what exactly does "unmerged" mean? Does >it mean not reduced to asymmetric unit? Or something happened much >earlier in data processing, like the "no partials" comment in COMBAT seems >to suggest? If it is the latter case, why is it so important for symmetry >analysis in POINTLESS? > >Regards, > >Weikai > > > ---------End of Included Message---------- Raji Edayathumangalam Postdoctoral Fellow The Rockefeller University Box 224, 1230 York Avenue New York, NY 10021
