enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Rhombohedron - Wikipedia

    en.wikipedia.org/wiki/Rhombohedron

    In geometry, a rhombohedron (also called a rhombic hexahedron [1] [2] or, inaccurately, a rhomboid [a]) is a special case of a parallelepiped in which all six faces are congruent rhombi. [3] It can be used to define the rhombohedral lattice system , a honeycomb with rhombohedral cells.

  3. Hexagonal crystal family - Wikipedia

    en.wikipedia.org/wiki/Hexagonal_crystal_family

    The trigonal crystal system consists of the 5 point groups that have a single three-fold rotation axis, which includes space groups 143 to 167. These 5 point groups have 7 corresponding space groups (denoted by R) assigned to the rhombohedral lattice system and 18 corresponding space groups (denoted by P) assigned to the hexagonal lattice system.

  4. Crystal system - Wikipedia

    en.wikipedia.org/wiki/Crystal_system

    The diamond crystal structure belongs to the face-centered cubic lattice, with a repeated two-atom pattern.. In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point).

  5. Trigonal trapezohedron - Wikipedia

    en.wikipedia.org/wiki/Trigonal_trapezohedron

    In geometry, a trigonal trapezohedron is a polyhedron with six congruent quadrilateral faces, which may be scalene or rhomboid. [1] [2] The variety with rhombus-shaped faces faces is a rhombohedron. [3] [4] An alternative name for the same shape is the trigonal deltohedron. [5]

  6. Rhombic dodecahedron - Wikipedia

    en.wikipedia.org/wiki/Rhombic_dodecahedron

    In geometry, the rhombic dodecahedron is a convex polyhedron with 12 congruent rhombic faces. It has 24 edges, and 14 vertices of 2 types. As a Catalan solid, it is the dual polyhedron of the cuboctahedron. As a parallelohedron, the rhombic dodecahedron can be used to tesselate its copies in space creating a rhombic dodecahedral honeycomb.

  7. Miller index - Wikipedia

    en.wikipedia.org/wiki/Miller_index

    With hexagonal and rhombohedral lattice systems, it is possible to use the Bravais–Miller system, which uses four indices (h k i ℓ) that obey the constraint h + k + i = 0. Here h , k and ℓ are identical to the corresponding Miller indices, and i is a redundant index.

  8. Crystal structure - Wikipedia

    en.wikipedia.org/wiki/Crystal_structure

    In monoclinic, trigonal, tetragonal, and hexagonal systems there is one unique axis (sometimes called the principal axis) which has higher rotational symmetry than the other two axes. The basal plane is the plane perpendicular to the principal axis in these crystal systems.

  9. Bravais lattice - Wikipedia

    en.wikipedia.org/wiki/Bravais_lattice

    All primitive unit cells with different shapes for a given crystal have the same volume by definition; For a given crystal, if n is the density of lattice points in a lattice ensuring the minimum amount of basis constituents and v is the volume of a chosen primitive cell, then nv = 1 resulting in v = 1/n, so every primitive cell has the same ...