Definition:
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.
Example:| 'P 21/n 21/m 21/a' | full symbol for Pnma |
Type: char
Mandatory item: no
Alias:Related items: _space_group.name_H-M_ref (alternate)
_space_group.name_H-M_alt (alternate)
Category: space_group
Copyright © 2005 International Union of Crystallography