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 exhibiting long-range order and symmetry. Patterns are located upon the points of a lattice, which is an array of points repeating periodically in three dimensions. The points can be thought of as forming identical tiny boxes, called unit cells, that fill the space of the lattice. The lengths of the edges of a unit cell and the angles between them are called the lattice parameters. The symmetry properties of the crystal are embodied in its space group.
A crystal's structure and symmetry play a role in determining many of its physical properties, such as cleavage, electronic band structure, and optical transparency.
Read more about Crystal Structure: Unit Cell, Classification, Grain Boundaries, Defects and Impurities, Prediction of Structure, Polymorphism, Physical Properties
Famous quotes containing the words crystal and/or structure:
“I waited alone, in the company of orchids, roses and violets who—like people waiting beside you, but to whom you are unknown—maintained a silence which their individuality of living things rendered more imposing and in their chilly manner received the heat from an incandescent coal fire, preciously placed behind a crystal glass, in a white marble tub where it dropped, from time to time, its dangerous rubies.”
—Marcel Proust (1871–1922)
“Agnosticism is a perfectly respectable and tenable philosophical position; it is not dogmatic and makes no pronouncements about the ultimate truths of the universe. It remains open to evidence and persuasion; lacking faith, it nevertheless does not deride faith. Atheism, on the other hand, is as unyielding and dogmatic about religious belief as true believers are about heathens. It tries to use reason to demolish a structure that is not built upon reason.”
—Sydney J. Harris (1917–1986)