Index

Macromolecular dictionary (mmCIF) version 2.0.09

_space_group.name_H-M_alt

Definition:

   _space_group.name_H-M_alt allows any Hermann-Mauguin symbol
   to be given. The way in which this item is used is determined
   by the user and in general is not intended to be interpreted by
   computer. It may, for example, be used to give one of the
   extended Hermann-Mauguin symbols given in Table 4.3.2.1 of
   International Tables for Crystallography Vol. A (2002) or
   a Hermann-Mauguin symbol for a conventional or unconventional
   setting.

   Each component of the space-group name is separated by a
   space or an underscore. The use of a space is strongly
   recommended.  The underscore is only retained because it
   was used in old CIFs. It should not be
   used in new CIFs. Subscripts should appear without special
   symbols. Bars should be given as negative signs before the
   numbers to which they apply.

   The commonly used Hermann-Mauguin symbol determines the space-
   group type uniquely but a given space-group type may be
   described by more than one Hermann-Mauguin symbol. The space-
   group type is best described using _space_group.IT_number.

   The Hermann-Mauguin symbol may contain information on the
   choice of basis, but not on the choice of origin. To
   define the setting uniquely, use _space_group.name_Hall or
   list the symmetry operations.

;                               loop_
                                   _space_group.name_H-M_alt
                                    'C m c m'
                                    'C 2/c 2/m 21/m'
                                    'A m a m'
;

Type: line

Mandatory item: no

Related item: _symmetry.space_group_name_H-M (alternate)

Category: space_group