Locating Octahedral Voids o Take a unit cell of ccp or fcc.
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The body center of the cube, C is not occupied but surrounded by six atoms on face centers.
o Joining the face centers creates a octahedron.
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Thus, this unit cell has one octahedral void at the body centre of the cube.
There is one octahedral void at the centre of each of the 12 edges.
It is surrounded by six atoms, three belonging to the same unit cell and three belonging to two adjacent unit cells.
Each edge of the cube and octahedral void are shared between four adjacent unit cells.
Only ΒΌ of each void belongs to a particular unit cell
In cubic close packed structure octahedral void at the body-center of the cube = 1