unit cell
Noun
Meaning
unit cell (plural unit cells)
(crystallography) The smallest repeating structure (parallelepiped) of atoms within a crystal, from which the structure of the complete crystal can be inferred.
Hypernyms
Examples
A crystal structure (an arrangement of atoms in a crystal) is characterized by its unit cell, a small imaginary box containing one or more atoms in a specific spatial arrangement.
By contrast, macromolecular crystallography often involves tens of thousands of atoms in the unit cell.
Greenwood, p. 1275 Chemical compounds Here a, b and c are lattice constants in picometers, No is space group number and Z is the number of formula units per unit cell ; fcc stands for the face-centered cubic symmetry.
Haüy's study led to the correct idea that crystals are a regular three-dimensional array (a Bravais lattice ) of atoms and molecules ; a single unit cell is repeated indefinitely along three principal directions that are not necessarily perpendicular.
Its Curie temperature is convert, meaning that bulk nickel is non-magnetic above this temperature. citation The unit cell of nickel is a face-centered cube with the lattice parameter of 0.352 nm, giving an atomic radius of 0.124 nm.
Limitations seeAlso As the crystal's repeating unit, its unit cell, becomes larger and more complex, the atomic-level picture provided by X-ray crystallography becomes less well-resolved (more "fuzzy") for a given number of observed reflections.