2.3.3.3.169. NXunit_cell¶
Status:
base class (contribution), extends NXobject
Description:
Base class to describe structural aspects of an arrangement of ...
Base class to describe structural aspects of an arrangement of atoms or ions including a crystallographic unit cell.
Following recommendations of CIF and International Tables of Crystallography.
Symbols:
d: Dimensionality of the lattice.
- Groups cited:
Structure:
reference_frame: (optional) NX_CHAR
Path to a reference frame in which the unit cell is defined ...
Path to a reference frame in which the unit cell is defined to resolve ambiguity in cases when e.g. a different reference frame than the NeXus default reference frame (McStas) was chosen.
dimensionality: (optional) NX_POSINT
Dimensionality of the structure. ...
Dimensionality of the structure.
Any of these values:
1
|2
|3
a_b_c: (optional) NX_NUMBER (Rank: 1, Dimensions: [d]) {units=NX_LENGTH}
Geometry of the unit cell quantified via parameters a, b, and c.
alpha_beta_gamma: (optional) NX_NUMBER (Rank: 1, Dimensions: [d]) {units=NX_ANGLE}
Geometry of the unit cell quantified via parameters alpha, beta, and gamma.
crystal_system: (optional) NX_CHAR
Crystal system. ...
Crystal system.
For a crystal system in 2D space monoclinic is an exact synonym for oblique. For a crystal system in 2D space orthorhombic is an exact synonym for rectangular. For a crystal system in 2D space tetragonal is an exact synonym for square.
Any of these values:
triclinic
monoclinic
orthorhombic
tetragonal
rhombohedral
hexagonal
cubic
laue_group: (optional) NX_CHAR
Laue group using International Table of Crystallography notation.
point_group: (optional) NX_CHAR
Point group using International Table of Crystallography notation.
space_group: (optional) NX_CHAR
Space group from the International Table of Crystallography notation.
is_centrosymmetric: (optional) NX_BOOLEAN
True if space group is considered a centrosymmetric one. ...
True if space group is considered a centrosymmetric one. False if space group is considered a non-centrosymmetric one.
Centrosymmetric has all types and combinations of symmetry elements (translation, rotational axis, mirror planes, center of inversion) Non-centrosymmetric compared to centrosymmetric is constrained (no inversion). Chiral compared to non-centrosymmetric is constrained (no mirror planes).
is_chiral: (optional) NX_BOOLEAN
True if space group is considered a chiral one. ...
True if space group is considered a chiral one. False if space group is consider a non-chiral one.
area: (optional) NX_NUMBER {units=NX_AREA}
Area of the unit cell if dimensionality is 2.
volume: (optional) NX_NUMBER {units=NX_VOLUME}
Volume of the unit cell if dimensionality is 3.
ATOM: (optional) NXatom
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.