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This type of crystal structure has a cubic unit cell with atoms centered at all eight corners, plus an atom centered in the middle of each of the six cube faces. The atoms touch each other along the face diagonal, and along the plane bisecting the cube in each of the three directions possible. So therefore each atom would be touching twelve other atoms. This pattern holds four atoms per unit cell. The atomic packing factor for a Body Centered Cubic crystalline structure is 0.74, which is the highest possible value for any arrangement of spheres of identical radius. The other arrangement that has this close packed arrangement is the Hexagonal Close Packed.

Some of the materials that are composed of Face Centered Cubic unit cells at room temperature include Copper, Nickel, Aluminum, Lead, Silver, Platinum, and Gold. Note that these metals tend to have high density. This is directly a result of the high atomic packing factor. They also tend to be quite ductile materials. This is due to their structure having four different so called "slip planes," planar vectors along which the layers of atoms are more likely to slide apart.

Face-Centered Cubic (FCC) is one of the three kinds of cubic lattice structures, Simple Cubic and Body-Centered Cubic being the others. It is one of the fourteen Bravais lattices. FCC lattices, along with HCP lattices, are the most efficient uses of space nature has in terms of solid state chemistry. Each unit cell of an FCC solid is considered to have 4 molecules.

In each unit cell of an FCC solid, there are molecules on each of the eight corners of the cube. In addition to this, there is a molecule on each of the six faces of the cube. This is why Face-Centered Cubic is called what it is: the extra molecules are on the faces of each unit cell, rather than wholly contained within the body, as in a body-centered cubic structure.

As stated before, the FCC structure is tied for the most efficient Bravais lattice. As a result, many elements naturally adopt FCC: gold, copper, silver, aluminum, cesium, nickel and lead are just a few.

Let's see why each unit cell is considered to have 4 molecules. As in SC and BCC, each molecule on the 8 corners of the cube are split between 8 unit cells, so they all collectively add up to one. In FCC, there is a molecule on each of the six faces of the cube, which is shared with one other unit cell, which means each one counts as half a molecule. They all add up to three. Together, these account for all four molecules per unit cell.

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