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NMR entries

Eldon Ulrich (elu@gir.nmrfam.wisc.edu)
Mon, 29 Apr 1996 09:59:56 -0500 

On Apr 28, 12:50am, herbert_bernstein wrote:
> Subject: NMR entries
> A suggestion -- until a more complete approach to NMR entries is
> worked out, could we not temporarily add the token
>   _atom_site.label_model_id
> which could be used to carry a model serial number or other
> identifier for multiple models in the same structure.  This
> would allow a direct mapping of the NMR structures currently
> in the PDB.  In the PDB NMR entries, each section of the atom
> list with coordinates for a given model is bracketed by
> MODEL/ENDMDL records which effectively associate a model serial
> number with the bracketed records.
>
> Non-NMR entries need not use this token, but it would close
> the largest open gap in mapping PDB entries to mmCIF entries.
>-- End of excerpt from herbert_bernstein

It has been suggested that the data tag '_atom_site.label_alt_id' could be used
to solve the problem described above without additional data tags being
created. Is there a specific problem or objection with implementing the
'_atom_site.label_alt_id' suggestion?  One objection has involved calculating
atom site occupancies.  However, the '_atom_site.occupancy' tag is not
mandatory and does not need to be included for NMR structures.

Eldon Ulrich