Hexakis

Hexakis is a prefix used in scientific nomenclature to denote sixfold multiplication or augmentation. The term derives from the Greek prefix hex- meaning six, combined with a productive suffix used in technical terms to indicate repetition or amplification. In practice, hexakis appears most often in chemistry and geometry to signal six identical elements, ligands, or face augmentations in a given object.

In chemistry and coordination chemistry, hexakis is used to name compounds in which a central atom or cluster is associated with six identical substituents or ligands. It is common in organometallic and inorganic nomenclature for describing highly substituted complexes or clusters where symmetry places six identical groups around a core. Examples generally describe six identical ligands such as phosphines, nitriles, or arene ligands bound to a metal center. The exact structure and oxidation state depend on the central atom and the nature of the ligands, and usage can vary among nomenclature traditions.

In geometry, hexakis denotes a class of polyhedra formed by the kis operation, which erects a pyramid on each face of a base polyhedron. The resulting solids are known as hexakis tetrahedron, hexakis octahedron, and related forms. These shapes arise in the study of Catalan solids and polyhedral duals and illustrate how a base polyhedron can be expanded by adding a pyramid to every face. The term emphasizes the sixfold aspect of the face augmentation process.

Notable instances include hexakis tetrahedron and hexakis octahedron, which exemplify the kis construction and the resulting highly faceted surfaces. See also kis (geometry) and chemical nomenclature prefixes.