Difficult datasets: Difference between revisions

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* [http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#NBATCH= NBATCH]= (total rotation range)/45  ! to reduce the number of scale factors; the value of NBATCH is shown as NXBIN in CORRECT.LP for the ABSORB and DECAY correction; default is (total rotation range)/5. Other values, like (total rotation range)/60 or (total rotation range)/90 might also be tried.
* [http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#NBATCH= NBATCH]= (total rotation range)/45  ! to reduce the number of scale factors; the value of NBATCH is shown as NXBIN in CORRECT.LP for the ABSORB and DECAY correction; default is (total rotation range)/5. Other values, like (total rotation range)/60 or (total rotation range)/90 might also be tried.
* [http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#CORRECTIONS= CORRECTIONS]= ABSORB  ! don't try to correct for MODULATION and DECAY in scaling
* [http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#CORRECTIONS= CORRECTIONS]= ABSORB  ! don't try to correct for MODULATION and DECAY in scaling
* FRIEDEL'S_LAW=TRUE unless the multiplicity is high. A clear sign that FRIEDEL'S_LAW=TRUE is required is that the CHI^2-VALUE OF FIT OF CORRECTION FACTORS is significantly below 1 (e.g. 0.5)


== optimizing the parameters for XSCALE ==
== optimizing the parameters for XSCALE ==


If you use XSCALE to merge several XDS datasets, you should make sure that you specify in XSCALE.INP the same values for NBATCH and CORRECTIONS as you do, in XDS.INP, for the CORRECT step.
If you use XSCALE to merge several XDS datasets, you should make sure that you specify in XSCALE.INP the same values for NBATCH and CORRECTIONS as you do, in XDS.INP, for the CORRECT step.
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