The face-centered cubic (FCC) structure is a type of crystal lattice where atoms are located at each corner and the centers of all the cube's faces. This arrangement allows for a high packing efficiency, with about 74% of the volume occupied by atoms. Common metals that exhibit the FCC structure include aluminum, copper, and gold. In the FCC lattice, each unit cell contains four atoms, as each corner atom is shared among eight adjacent cells and each face-centered atom is shared between two cells. This structure contributes to the ductility and strength of FCC metals, making them useful in various applications, including construction and electronics.