New version (2.3) of core CIF dictionary available

[Howard Flack]

_geom_angle_site_symmetry

 One typo, one problem and one question:

   typo: "equivalent position number 'n'" should be "equivalent position
code 'n'"

   problem: Ton and Tony have cases where addding +5 to save having
negative numbers is too small. klm needs generalizing. coreCIFchem need
to be informed at the appropriate moment when thinking about molecules.

   question:  Does the publication  Hall, S. R. (1981). Acta Cryst. A37,
517-525 specify and guarantee a unique "equivalent position code 'n'"
for each and every symmetry operation in the space group (i.e. the
infinite number of operations) and does the definition of
_symmetry_space_group_name_Hall imply that this code is implemented. Is
the Hall symbol unique for each space group and setting? If not, do
different Hall symbols for the same space group and setting give an
identical list of symmetry operations with their equivalent position
codes (if these are indeed defined)? 


  comment:  What fun!
H.