2.3.3.3.51. NXcg_grid¶
Status:
base class (contribution), extends NXcg_primitive
Description:
Computational geometry description of a grid of Wigner-Seitz cells in Euclidean ...
Computational geometry description of a grid of Wigner-Seitz cells in Euclidean space.
Three-dimensional grids with cubic cells are if not the most frequently used example of such grids. Numerical methods and models that use grids are used in many cases in the natural sciences and engineering disciplines. Examples are discretizations in space and time used for phase-field, cellular automata, or Monte Carlo modeling.
Symbols:
The symbols used in the schema to specify e.g. dimensions of arrays.
d: The dimensionality of the grid.
c: The cardinality or total number of cells aka grid points.
n_b: Number of boundaries of the bounding box or primitive housing the grid.
- Groups cited:
Structure:
origin: (optional) NX_NUMBER (Rank: 1, Dimensions: [d]) {units=NX_ANY}
Location of the origin of the grid. ...
Location of the origin of the grid.
Use the depends_on field that is inherited from the NXcg_primitive class to specify the coordinate system in which the origin location is defined.
symmetry: (optional) NX_CHAR
The symmetry of the lattice defining the shape of the unit cell. ...
The symmetry of the lattice defining the shape of the unit cell.
Obligatory value:
cubiccell_dimensions: (optional) NX_NUMBER (Rank: 1, Dimensions: [d]) {units=NX_LENGTH}
The unit cell dimensions using crystallographic notation.
extent: (optional) NX_INT (Rank: 1, Dimensions: [d]) {units=NX_UNITLESS}
Number of unit cells along each of the d unit vectors. ...
Number of unit cells along each of the d unit vectors.
The total number of cells or grid points has to be the cardinality. If the grid has an irregular number of grid positions in each direction, as it could be for instance the case of a grid where all grid points outside some masking primitive are removed, this extent field should not be used. Instead, use the coordinate field.
position: (optional) NX_NUMBER (Rank: 2, Dimensions: [c, d]) {units=NX_ANY}
Position of each cell in Euclidean space.
coordinate: (optional) NX_INT (Rank: 2, Dimensions: [c, d]) {units=NX_DIMENSIONLESS}
Coordinate of each cell with respect to the discrete grid.
number_of_boundaries: (optional) NX_INT {units=NX_UNITLESS}
Number of boundaries distinguished ...
Number of boundaries distinguished
Most grids discretize a cubic or cuboidal region. In this case six sides can be distinguished, each making an own boundary.
boundaries: (optional) NX_CHAR (Rank: 1, Dimensions: [n_b])
Name of domain boundaries of the simulation box/ROI ...
Name of domain boundaries of the simulation box/ROI e.g. left, right, front, back, bottom, top.
boundary_conditions: (optional) NX_INT (Rank: 1, Dimensions: [n_b]) {units=NX_UNITLESS}
The boundary conditions for each boundary: ...
The boundary conditions for each boundary:
0 - undefined 1 - open 2 - periodic 3 - mirror 4 - von Neumann 5 - Dirichlet
surface_reconstruction: (optional) NX_CHAR
Details about the computational geometry method and implementation ...
Details about the computational geometry method and implementation used for discretizing internal surfaces as e.g. obtained with marching methods, like marching squares or marching cubes.
Documenting which specific version was used helps with understanding how robust the results are with respect to the topology of the triangulation. Reference to the specific implementation of marching cubes used.
See for example the following papers for details about how to identify a DOI which specifies the implementation used:
The value placed here should ideally be an identifier of a program. If not possible, an identifier for a paper, technical report, or free-text description can be used instead.
bounding_box: (optional) NXcg_polyhedron
A tight bounding box about the grid.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.
