In
chemistry, 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 dete ...
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 elec ...
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 ...
(a
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, 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