Hi Manoj As regards the HKL .sca file, it depends on what type of .sca file it is - there are two types, one which has the reflections merged into unique reflections (so, for example, there will be one entry for the (-8 5 6) reflection) and the other which does not have the equivalent reflections merged (so there may be several entries for the (-8, 5, 6) reflection).
The second is more informative as regards the anomalous signal and is what I use when running, for example, hkl2map. If you only have the former, I would recommend asking your collaborator to give you the second type (they may need to re-run scalepack with the 'scale anomalous' flag set. I haven't used Xtriage so I can't comment on how useful it is - other people do seem to like it, though! Using Mosflm, I think the phrase (borrowed from a sportswear company) is "just do it". In other words, you need to do little more than just process the data with iMosflm and run the "QuickScale" task at the end; the "little more" is to open the "Processing Options" under the "settings" menu, and check the "output unmerged observations from Aimless" option (this will give you both types of scalepack style .sca files, in addition to mtz files). The output from QuickScale will start the ccp4 results viewer, and the Aimless output should give you a good indication (via the values/plots for "DelAnom correlation between half-sets" and the "Mid-slope of Anom Normal Probability") of whether you have a significant anomalous signal or not. HTH Harry -- Dr Harry Powell Chairman of European Crystallographic Association SIG9 (Crystallographic Computing) On 22 Mar 2018, at 01:05, Manoj Saxena wrote: > Hi all, > I have a dataset for which I got the .sca file from a collaborator and I am > trying to look at the strength of the anomalous signal. Looking at archives > in the CCP4bb I found many people suggesting using the Chi**2 values > using ScaLAPACK using HKL2000. > However, at the moment, I have access only to Xtriage from Phenix which gives > a clear graph showing that my data has no significant difference anomalous > signal. So my question is how reliable is this analysis by Xtriage and is it > possible that during data processing anomalous scattering difference was lost. > I would like to reprocess the data using mosflm any suggestions for data > processing (to see the anomalous signal) > would be appreciated. > > > Thanks > > Manoj Saxena > Postdoc > University of Puerto Rico >
