Good Morning,
I am solving a structure with 6-fold NCS and consequently used sftools
to select a 5% test set of reflections in thin resolution shells to
monitor Rfree.
I have reprocessed the same dataset to higher resolution to improve the
quality of the electron density maps and now need to extend the test
set.
There appears to be no direct method in sftools of keeping the same
test set while adding an additional set in the same proportion to
higher resolution, also in thin shells.
The only way I can see this might be done is to:
1. SELECT RESOL > to give the high resolution shell of reflections
2. Generate the test set from the high resolution shell using RFREE
0.05 SHELL.
3. SELECT RESOL > to produce a reflection file with the same resolution
range as the old dataset.
4. READ [old dataset] COL RFREE.
5. SELECT COL RFREE=0.
6. SELECT ALL to include all reflections.
7. WRITE New_Dataset.mtz.
The result should be a higher resolution dataset, with 5% test set of
reflections in thin resolution shells, keeping the same test
reflections as the old set.
Will this work, or is there an alternative reliable procedure?
Best wishes,
Michael
Michael Roberts
Crysalin Limited
Cherwell Innovation Centre
77 Heyford Park
Upper Heyford
Oxfordshire OX25 5HD
Phone: 01869 238030
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