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Symmetry dictionary (symCIF) version 1.0.1




   The full international Hermann-Mauguin space-group symbol as
   defined in Section 2.2.3 and given as the second item of the
   second line of each of the space-group tables of Part 7 of
   International Tables for Crystallography Volume A (2002).

   Each component of the space-group name is separated by a
   space or an underscore character. 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 or _space_group.name_Schoenflies. The
   full international Hermann-Mauguin symbol contains information
   about the choice of basis for monoclinic and orthorhombic
   space groups but does not give information about the choice
   of origin. To define the setting uniquely use
   _space_group.name_Hall, list the symmetry operations
   or generators, or give the transformation relating
   the setting used to the reference setting defined in this
   dictionary under _space_group.reference_setting.

   Ref: International Tables for Crystallography (2002). Volume A,
        Space-group symmetry, edited by Th. Hahn, 5th ed.
        Dordrecht: Kluwer Academic Publishers.


'P 21/n 21/m 21/a' full symbol for Pnma

Type: char

Mandatory item: no

symmetry.space_group_name_H-M (cif_mm.dic version 1.0.0)

Related items: _space_group.name_H-M_ref (alternate)
_space_group.name_H-M_alt (alternate)

Category: space_group