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2QVO.xds: Difference between revisions
→SHELXC/D/E structure solution
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The resulting output files are XYCORR.LP, INIT.LP, COLSPOT.LP, IDXREF.LP, DEFPIX.LP, INTEGRATE.LP and CORRECT.LP. Data files are XPARM.XDS (from IDXREF), and the XDS_ASCII.HKL file all of which can be downloaded from [[Media:Xds_2qvo.tar.bz2.png|here]]. | The resulting output files are XYCORR.LP, INIT.LP, COLSPOT.LP, IDXREF.LP, DEFPIX.LP, INTEGRATE.LP and CORRECT.LP. Data files are XPARM.XDS (from IDXREF), and the XDS_ASCII.HKL file all of which can be downloaded from [[Media:Xds_2qvo.tar.bz2.png|here]]. | ||
==Optimization of data reduction== | |||
The only safe way to optimize the data reduction is to look at external quality indicators. Internal R-factors, and even the correlation coefficient of the anomalous signal are of relatively little value. A readily available external quality indicator is CCmax/CCweak as obtained by SHELXD. | |||
One candidate for optimization is MAXIMUM_ERROR_OF_SPOT_POSITION. By default this is 3.0 . In the case of these data, this default appears to be very small, because the STANDARD DEVIATION OF SPOT POSITION (PIXELS) is quite high (1.5 and more). This prevents XDS from using all the reflections for geometry refinement. | |||
I found that MAXIMUM_ERROR_OF_SPOT_POSITION=6.0 significantly improved the CCmax/CCweak indicators. | |||
==SHELXC/D/E structure solution== | ==SHELXC/D/E structure solution== | ||
generate XDSCONV.INP (a trick is to use MERGE=TRUE, for some reason the results are better that way) and run xdsconv and shelxc: | |||
This is done in a subdirectory of the XDS data reduction directory. Here, we generate XDSCONV.INP (a trick is to use MERGE=TRUE, for some reason the results are better that way) and run xdsconv and shelxc: | |||
#!/bin/csh -f | #!/bin/csh -f | ||