The number of bonds formed by the central atom in a metal-ligand complex.
In chemistry and crystallography, the coordination number of a central atom in a molecule or crystal is the number of its nearest neighbours. This number is determined somewhat differently for molecules than for crystals. In chemistry, the emphasis is on bonding structure in molecules or ions and the coordination number of an atom is determined by...
the number of atoms, ions, or molecules that a central atom or ion holds as its nearest neighbours in a complex or coordination compound or in a ... [1 related articles]
The coordination number of a specified atom in a chemical species is the number of other atoms directly linked to that specified atom [cf. IUPAC INORGANIC NOMENCLATURE (1990); Rule I-10.2.5]. For example, the coordination number of carbon in methane is four, and it is five in protonated methane, CH5+. (The term is used in a di...
the number of atomic or ionic nearest neighbors.
In describing crystals, the number of nearest neighbours of an atom or ion. The number of donor atoms coordinated to a metal.
the number of atomic or ionic nearest neighbors.
In describing crystals, the number of nearest neighbours of an atom or ion.The number of donor atoms coordinated to a metal.
The number of atomic or ionic nearest neighbours. 
the number of anions surrounding a single cation in a stable crystal structure.