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atom numbering in mmCIF

Frances Bernstein (bernstei@fcb.pdb.bnl.gov)
Fri, 20 Oct 1995 15:58:48 -0400


According to the mmCIF dictionary,

;              The value of _atom_site.id must uniquely identify a record in
the
               ATOM_SITE list.

Thus it would not be permitted to use the same _atom_site.id for the 'same'
atom
each time it occurs in different models.

For the 'same' atom in different models, all the identification fields
(atom name, residue name, chain, etc.) are identical; the only difference is
in the atom number and, of course, the coordinates.

One could, of course, make a separate entry out of each model but that
would become quite unwieldly with the large number (>>50) of models that
are deposited for some structures.