Keating model

In physics, The Keating Model is a model that theoretical physicist Patrick N. Keating introduced in 1966 to describe forces induced on neighboring atoms when one atom moves in a solid. In physics, The Keating Model is a model that theoretical physicist Patrick N. Keating introduced in 1966 to describe forces induced on neighboring atoms when one atom moves in a solid. The term most often applies to the forces on first- and second-nearest neighboring atoms that arise when an atom is moved in tetrahedrally-bonded solids, such as diamond, silicon, germanium, and a number of other covalent crystals with the diamond or zinc blende structures. Crystalline solids generally consist of an ordered array of interconnected atoms, generated by repetition of a unit cell in three dimensions, and are of two extreme types—ionic crystals, and covalent crystals. Others are intermediate: partly ionic and partly covalent. Ionic crystals are made up of quite different ions, such as Na+ and Cl− in common salt, for example, while covalent crystals such as diamond are made up of atoms that share electrons in a covalent bond.