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THE FACE-CENTERED CUBIC LATTICE |
| THE BASIC LATTICE The face-centered cubic lattice is one of the most common types of crystal lattices. In addition to the eight atoms located at the corners of the cube, the face-centered cell contains an additional atom on each face of the cube. The face-centered cubic lattice is adopted by many elements, including Ca, Sr,Al, Ni, Cu, Rh, Pd, Ag, Ir, Pt, Au, and Pb. This illustration shows two unit cells of the face-centered cubic lattice. View a VRML model of the face-centered cubic lattice |
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HEXAGONAL LAYERS The face-centered cubic lattice can be alternately viewed as a series of stacked hexagonal layers stacked in an ABC fashion. These are represented here by the blue, red, and green cylinders. |
| OCTAHEDRAL HOLES
There exists two different types of spaces or holes within a series of stacked hexagonal layers. This illustration shows in green the location of two octahedral holes. The term octahedral is derived from the fact that the resulting space has eight sides. T Many ionic compounds adopt a structure in which one set of ions forms a face-centered cubic array and the other set of ions reside within the octahedral holes. The rock salt (halite) structure is one example |
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TETRAHEDRAL HOLES
The second type of space that can exist between stacked hexagonal layers
is called a tetrahedral hole. This illustration shows in green the
location of four tetrahedral holes in the two unit cells shown..
A tetrahedral hole is formed by three atoms in one hexagonal layer and
a single atom in the layer above or beneath. |
Additional Links
Crystal Structure Home Page
Introduction to Close-Packed Structures
The Hexagonal Close-Packed Structure
The Face-Centered Cubic Lattice
The Halite Structure
The Fluorite Structure
The Zinc Blende Structure
The Diamond Structure