Difficult datasets: Difference between revisions

Difficult datasets (view source)

12 bytes added , 13 August 2019

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 * [http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#NBATCH= NBATCH]= (total angular 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 angular rotation range)/5. Other values, like (total rotation range)/60 or (total rotation range)/90 might also be tried. Try to match NBATCH with DELPHI (see above).
 * maybe [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 because these may be poorly determined; however in general it helps to correct for them
-* 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). If in doubt use the setting that maximizes ISa.
+* FRIEDEL'S_LAW=TRUE unless there is a known anomalous scatterer. 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). If in doubt use the setting that maximizes ISa.
 == optimizing the parameters for XSCALE ==