Close-packing of spheres — hcp and fcc close packing of spheres In geometry, close packing of spheres is a dense arrangement of equal spheres in an infinite, regular arrangement (or lattice). Carl Friedrich Gauss proved that the highest average density – that is, the… … Wikipedia
Cubic crystal system — A rock containing three crystals of pyrite (FeS2). The crystal structure of pyrite is simple cubic, and this is reflected in the cubic symmetry of its natural crystal facets … Wikipedia
Sphere packing — In mathematics, sphere packing problems are problems concerning arrangements of non overlapping identical spheres which fill a space. Usually the space involved is three dimensional Euclidean space. However, sphere packing problems can be… … Wikipedia
Atomic packing factor — In crystallography, atomic packing factor (APF) or packing fraction is the fraction of volume in a crystal structure that is occupied by atoms. It is dimensionless and always less than unity. For practical purposes, the APF of a crystal structure … Wikipedia
Crystal structure — In mineralogy and crystallography, crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a pattern, a set of atoms arranged in a particular way, and a lattice… … Wikipedia
Kepler conjecture — In mathematics, the Kepler conjecture is a conjecture about sphere packing in three dimensional Euclidean space. It says that no arrangement of equally sized spheres filling space has a greater average density than that of the cubic close packing … Wikipedia
Periodic table (crystal structure) — The structures of metallic elements adopted at normal temperatures are colour coded and shown below Greenwood Earnshaw] , the only exception is mercury, Hg, which is a liquid and the structure refers to the low temperature form. The melting… … Wikipedia
Colloidal crystal — A colloidal crystal is an ordered array of colloid particles, analogous to a standard crystal whose repeating subunits are atoms or molecules.[1] A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a… … Wikipedia
Lennard-Jones potential — Computational physics Numerical analysis … Wikipedia
Convex uniform honeycomb — The alternated cubic honeycomb is one of 28 space filling uniform tessellations in Euclidean 3 space, composed of alternating yellow tetrahedra and red octahedra. In geometry, a convex uniform honeycomb is a uniform tessellation which fills three … Wikipedia