Crystallography Online: the website of the International Union of Crystallography

David:

   Concerning _geom_bond_multiplicity, I maintain my objection to the 
version circulated on the 11th July and to the various other 
modifications suggested by you and by me.  Having studied your remarks, 
I really find no need at all to allow the possibility of giving the 
multiplicity in a full bond list.  With a full bond list, the 
multiplicity should be outlawed. The only reasonable options are:


An example showing a listing of only the symmetry unique bonds
N.B. With _geom_bond_multiplicity present, _geom_bond_site_symmetry_2 is 
forbidden.

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_multiplicity
Ca1   F1   2.495(9)    1
Ca1   F2   2.291(10)   2
Ca1   F2   2.391(11)   2
Ca1   F3   2.214(11)   2
Cr1   F1   1.940(11)   2
Cr1   F2   1.918(9)    2
Cr1   F3   1.848(10)   2

An example of a full bond list
With _geom_bond_site_symmetry_2 present,  is _geom_bond_multiplicity 
forbidden.

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
Ca1   F1   1_555  2.495(9)
Ca1   F2   1_555  2.291(10)
Ca1   F2   2_555  2.291(10)
Ca1   F2   3_565  2.391(11)
Ca1   F2   4_555  2.391(11)
Ca1   F3   2_545  2.214(11)
Ca1   F3   5_555  2.214(11)
Cr1   F1   1_555  1.940(11)
Cr1   F1   2_555  1.940(11)
Cr1   F2   1_555  1.918(9)
Cr1   F2   2_555  1.918(9)
Cr1   F3   1_555  1.848(10)
Cr1   F3   2_555  1.848(10)

   The two lists have different uses and both may be present.

H.