chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

, the tricapped trigonal prismatic

molecular geometry Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths, bond angles, torsional angles and any other geometrical parameters that determ ...

describes the shape of compounds where nine atoms, groups of atoms, or

ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...

s are arranged around a central atom, defining the vertices of a

triaugmented triangular prism The triaugmented triangular prism, in geometry, is a convex polyhedron with 14 equilateral triangles as its faces. It can be constructed from a triangular prism by attaching equilateral square pyramids to each of its three square faces. The sa ...

trigonal prism In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The oc ...

with an extra atom attached to each of its three rectangular faces). It is very similar to the

capped square antiprismatic molecular geometry In chemistry, the capped square antiprismatic molecular geometry describes the shape of compounds where nine atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a gyroelongated square pyramid. The gyro ...

, and there is some dispute over the specific geometry exhibited by certain molecules.

Examples

* is usually considered to have a tricapped trigonal prismatic geometry, although its geometry is sometimes described as capped square antiprismatic instead. * (Ln = La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy) * {{MolecularGeometry Stereochemistry Molecular geometry