NationMaster - Encyclopedia: Cubic crystal

In crystallography, the cubic crystal system (or isometric crystal system) is the most symmetric of the 7 crystal systems. The system is composed of the three Bravais lattices whose symmetry group is that of a cube. Crystallography (from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and graphein = write) is the experimental science of determining the arrangement of atoms in solids. ... Square with symmetry group D<sub>4</sub> Symmetry is a characteristic of geometrical shapes, equations, and other objects; we say that such an object is symmetric with respect to a given operation if this operation, when applied to the object, does not appear to change it. ... In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... In geometry and crystallography, a Bravais lattice is an infinite set of points generated by a set of discrete translation operations. ... The symmetry group of an object (e. ... A cube (or regular hexahedron) is a three-dimensional Platonic solid composed of six square faces, with three meeting at each vertex. ...

The cubes drawn are the conventional unit cells. For a cube whose vertices include 000 and 200, bcc has additional lattice point 111, while fcc has 110, 101, and 011. For bcc the primitive cells have a volume of 1/2 of the cube, e.g. the parallelepiped 000 200 020 220 111 311 131 331 with primitive translation vectors 200, 020, and 111, with determinant 4. For fcc the primitive cells have a volume of 1/4 of the cube, e.g. the parallelepiped 110 220 020 130 101 211 011 121 with primitive translation vectors 110, -1 1 0, and 0 -1 1, with determinant 2. Cubic crystal structure. ... Image File history File links Cubic-body-centered. ... Image File history File links Cubic-face-centered. ... The ordinary meaning of lattice is the basis for several technical usages A cherry lattice pastry A mathematical lattice that is a type of partially ordered set. ... In solid state physics and mineralogy, particularly in describing crystal structure, a primitive cell is a minimum volume cell corresponding to a single lattice point. ... In geometry, a parallelepiped or parallelopipedon is a three-dimensional figure like a cube, except that its faces are not squares but parallelograms. ...

As can be seen by turning the base plane 45°, bcc and fcc only differ by a vertical scaling: in both cases the lattice points in the middle layer are above the centers of the squares of the base layer. Both scales are "special", allowing a cubic symmetry: for bcc the middle layer has a height of 1/2 of the grid size of the square grid of each layer, while for fcc the middle layer has a height of 1/2 √2 of that grid size. For other scalings both are the same, body-centered tetragonal. In crystallography, the tetragonal crystal system is one of the 7 lattice point groups. ...

Perpendicular to each body diagonal, fcc has hexagonal layers, with three positionings, which are cyclically changed. Two opposite vertices of the cube have two layers in between. See also: close-packing Close-packing of spheres refers to arranging an infinite lattice of spheres so that they take up the greatest possible fraction of an infinite 3-dimensional space. ...

The point groups that fall under this crystal system are listed below, followed by their representations in international notation and Schoenflies notation, and mineral examples. In crystallography, a crystallographic point group or crystal class is a set of symmetry operations that leave a point fixed, like rotations or reflections, which leave the crystal unchanged. ... In crystallography, a crystallographic point group or crystal class is a set of symmetry operations that leave a point fixed, like rotations or reflections, which leave the crystal unchanged. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ...

There are 36 cubic space groups, of which 10 are hexoctahedral: Fd3c, Fd3m, Fm3c, Fm3m, Ia3d, Im3m, Pm3m, Pm3n, Pn3m, and Pn3n. Other terms for hexoctahedral are normal class, holohedral, ditesseral central class, galena type. Galena is a lead ore. ... Cuprite Cuprite is a mineral composed of copper(I) oxide Cu2O, and is an important ore of copper. ... The mineral pyrite, or iron pyrite, is iron disulfide, FeS2. ... Sphalerite sample Another sphalerite sample Sphalerite (ZnS) is a mineral that is the chief ore of zinc. ...

Halite structure

Sodium chloride forms fcc crystals. In these, the larger chloride ions are arranged in a cubic close-packing, while the smaller sodium ions fill the octahedral gaps between them. Each ion is surrounded by six of the other kind. This same basic structure is found in many other minerals, and is known as the halite structure. Crystal structure for sodium chloride Drawn using IsisDraw by User:Walkerma Sodium Chloride Smells File links The following pages link to this file: Ionic crystal Sodium chloride Categories: Public domain images ... Crystal structure for sodium chloride Drawn using IsisDraw by User:Walkerma Sodium Chloride Smells File links The following pages link to this file: Ionic crystal Sodium chloride Categories: Public domain images ... Flash point Non-flammable R/S statement R: none S: none RTECS number VZ4725000 Supplementary data page Structure and properties n, Îµr, etc. ... Close-packing of spheres refers to arranging an infinite lattice of spheres so that they take up the greatest possible fraction of an infinite 3-dimensional space. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... Flash point Non-flammable R/S statement R: none S: none RTECS number VZ4725000 Supplementary data page Structure and properties n, Îµr, etc. ... Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... An ion is an atom or group of atoms with a net electric charge. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... Halite is the mineral of sodium chloride, NaCl, commonly known as rock salt. ...

The sodium ions indicated in blue show that the fcc lattice can also be represented by mid-edge and centered lattice points, without lattice points at the vertices of the cube.

Halite structure GA_googleFillSlot("encyclopedia_square");

See also

Halite structure