Item _space_group.name_H-M_alt
Description
*.name_H-M_alt allows for an alternative Hermann-Mauguin symbol
to be given. The way in which this item is used is determined
by the user and should be described in the item
_space_group.name_H-M_alt_description. It may, for example, be
used to give one of the extended Hermann-Mauguin symbols given
in Table 4.3.1 of International Tables for Crystallography
Vol A (1995) or a full Hermann-Mauguin symbol for an
unconventional setting.
Each component of the space group name is separated by a
space or an underscore. The use of space is strongly
recommended. The underscore is only retained because it
was used in earlier archived files. 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 the *.IT_number or *.name_Schoenflies.
The Hermann-Mauguin symbol may contain information on the
choice of basis though not on the choice of origin. To
define the setting uniquely use *.name_Hall, list the
symmetry operations or generators, or give the transformation
that relates the setting to the reference setting defined
in this dictionary under *.reference_setting.
Category
space_group
Item Examples
Example 1:
three examples for the space group number 63.
loop_
_space_group.name_H-M_alt
_space_group.name_H-M_alt_description
'C m c m(b n n)' 'Extended Hermann-Mauguin symbol'
'C 2/c 2/m 21/m' 'Full unconventional Hermann-Mauguin symbol'
'A m a m' 'Hermann-Mauguin symbol corresponding to setting used'
Mandatory Code
no
Data Type Code
char
Alias Names
| Alias Name |
Dictionary |
Version |
| _symmetry_space_group_name_H-M |
cif_core.dic |
1.0 |
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