enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 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).

  3. Allotropes of boron - Wikipedia

    en.wikipedia.org/wiki/Allotropes_of_boron

    Well known crystalline forms are α-rhombohedral (α-R), β-rhombohedral (β-R), and β-tetragonal (β-T). In special circumstances, boron can also be synthesized in the form of its α-tetragonal (α-T) and γ-orthorhombic (γ) allotropes. Two amorphous forms, one a finely divided powder and the other a glassy solid, are also known.

  4. Hexagonal crystal family - Wikipedia

    en.wikipedia.org/wiki/Hexagonal_crystal_family

    However, the rhombohedral axes are often shown (for the rhombohedral lattice) in textbooks because this cell reveals the 3 m symmetry of the crystal lattice. The rhombohedral unit cell for the hexagonal Bravais lattice is the D-centered [ 1 ] cell, consisting of two additional lattice points which occupy one body diagonal of the unit cell with ...

  5. Triply periodic minimal surface - Wikipedia

    en.wikipedia.org/wiki/Triply_periodic_minimal...

    Numerous examples are known with cubic, tetragonal, rhombohedral, and orthorhombic symmetries. Monoclinic and triclinic examples are certain to exist, but have proven hard to parametrise. [1] TPMS are of relevance in natural science. TPMS have been observed as biological membranes, [2] as block copolymers, [3] equipotential surfaces in crystals ...

  6. List of space groups - Wikipedia

    en.wikipedia.org/wiki/List_of_space_groups

    R rhombohedral; A reflection plane m within the point groups can be replaced by a glide plane, labeled as a, b, or c depending on which axis the glide is along. There is also the n glide, which is a glide along the half of a diagonal of a face, and the d glide, which is along a quarter of either a face or space diagonal of the unit cell.

  7. Periodic table (crystal structure) - Wikipedia

    en.wikipedia.org/wiki/Periodic_table_(crystal...

    Rhombohedral: R 3 m (No. 166) 105 (rh.) 315 (hex.) Partly due to its complexity, whether this structure is the ground state of Boron has not been fully settled. α-As: A7: Rhombohedral: R 3 m (No. 166) 2 (rh.) 6 (hex.) in grey metallic form, each As atom has 3 neighbours in the same sheet at 251.7pm; 3 in adjacent sheet at 312.0 pm. [18]

  8. Rhombohedron - Wikipedia

    en.wikipedia.org/wiki/Rhombohedron

    It can be used to define the rhombohedral lattice system, a honeycomb with rhombohedral cells. A rhombohedron has two opposite apices at which all face angles are equal; a prolate rhombohedron has this common angle acute, and an oblate rhombohedron has an obtuse angle at these vertices.

  9. Orthorhombic crystal system - Wikipedia

    en.wikipedia.org/wiki/Orthorhombic_crystal_system

    In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base ( a by b ) and height ( c ), such that a , b , and c are distinct.