Index

Macromolecular dictionary (mmCIF) version 2.0.09

Category CHEMICAL_CONN_ATOM

Name:
'chemical_conn_atom'

Description:

   Data items in the CHEMICAL_CONN_ATOM category would not, in
   general, be used in a macromolecular CIF. See instead the
   ENTITY data items.

   Data items in the CHEMICAL_CONN_ATOM and CHEMICAL_CONN_BOND
   categories record details about the two-dimensional (2D)
   chemical structure of the molecular species. They allow
   a 2D chemical diagram to be reconstructed for use in a
   publication or in a database search for structural and
   substructural relationships.

   The CHEMICAL_CONN_ATOM data items provide information about the
   chemical properties of the atoms in the structure. In cases
   where crystallographic and molecular symmetry elements coincide,
   they must also contain symmetry-generated atoms, so that the
   CHEMICAL_CONN_ATOM and CHEMICAL_CONN_BOND data items will always
   describe a complete chemical entity.

Example:

Example 1 - based on data set DPTD of Yamin, Suwandi, Fun, Sivakumar & bin Shawkataly [Acta Cryst. (1996), C52, 951-953].
 
    loop_
    _chemical_conn_atom.number
    _chemical_conn_atom.type_symbol
    _chemical_conn_atom.display_x
    _chemical_conn_atom.display_y
    _chemical_conn_atom.NCA
    _chemical_conn_atom.NH
        1   S    .39  .81   1   0
        2   S    .39  .96   2   0
        3   N    .14  .88   3   0
        4   C    .33  .88   3   0
        5   C    .11  .96   2   2
        6   C    .03  .96   2   2
        7   C    .03  .80   2   2
        8   C    .11  .80   2   2
        9   S    .54  .81   1   0
        10  S    .54  .96   2   0
        11  N    .80  .88   3   0
        12  C    .60  .88   3   0
        13  C    .84  .96   2   2
        14  C    .91  .96   2   2
        15  C    .91  .80   2   2
        16  C    .84  .80   2   2



Category groups:
    inclusive_group
    chemical_group
Category key:
    _chemical_conn_atom.number

Mandatory category: no