Octahedral hole

Definition

An octahedral hole is a void in a crystal lattice structure where an atom or ion can fit, surrounded by six atoms or ions arranged at the vertices of an octahedron. It is commonly found in close-packed structures such as face-centered cubic (FCC) and hexagonal close-packed (HCP) lattices.

5 Must Know Facts For Your Next Test

1. Octahedral holes are larger than tetrahedral holes and can accommodate larger cations in ionic crystals.
2. Each unit cell in a face-centered cubic (FCC) lattice contains four octahedral holes.
3. In ionic compounds, octahedral holes are typically occupied by cations while anions form the surrounding lattice.
4. The coordination number of an atom or ion in an octahedral hole is six because it is surrounded by six neighboring atoms or ions.
5. Octahedral holes are located at the edge centers and body center of the unit cell in FCC structures.

Review Questions

Related terms

Tetrahedral Hole: A smaller void in a crystal lattice where an atom or ion fits, surrounded by four atoms or ions arranged at the vertices of a tetrahedron.

Face-Centered Cubic (FCC): A type of crystal structure where atoms are located at each corner and the centers of all the faces of the cube, leading to high packing efficiency.

Hexagonal Close-Packed (HCP): A crystal structure where each layer of atoms is packed closely together, with alternating layers fitting into depressions formed by previous layers.