Pointless: Difference between revisions

1,029 bytes added ,  16 September 2014
attention space groups 17 and 18 !
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(attention space groups 17 and 18 !)
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will make an R-factor search for the correct origin.
will make an R-factor search for the correct origin.
'''Attention''': the space group number that pointless writes into the logfile (e.g. "18") is the generic one (as in the International Tables vol A), not the specific one (which could be 18, 2018 or 3018) that is used as a special convention within CCP4 to encode which of a,b and c is the two-fold axis. At the same time, pointless re-indexes orthorhombic such that a<b<c : this is what is called "cell-based setting" in the pointless documentation. However, users of [[XDSCONV]] want the "symmetry-based setting" because XDSCONV does not understand 2018 and 3018 (and those numbers are not even in the logfile, only in the MTZ file which is not used by XDSCONV anyway).
The upshot is: for space groups 17 and 18, one wants to use the "symmetry-based setting". It does not hurt to always (i.e. for all 65 space groups that proteins crystallize in) use it, so an easy way is e.g.:
echo -e SETTING SYMMETRY-BASED\\n CHIRALITY CHIRAL | pointless xdsin XDS_ASCII.HKL
which also shows how to send several commands to pointless.


See also:  
See also:  
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