Hi all,
if the xray data reach real atomic resolution (say <1A), one can nicely
refine cofactors w/o restraints.
In intermediate cases, the existence of multiple copies allows to use
the "SAME" option in SHELX refinement to restrain identical molecules to
each other, somewhat like NCS, but on bonds and angles.
Is there a possibility to do something similar with PHENIX? I have
structures with up to 16 or more copies in the ASU (and several copies
per chain), and 1.1A resolution. This would give me a very stable way to
access unbiased information about stereochemistry. (Using NCS is of
course not an powerful idea, as the torsion angles might vary between
the different copies).
Thanks for feedback,
Eckhard
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Eckhard Hofmann