How many total octahedral voids are present in a cubic unit cell?
Answer & explanation
Correct answer: option 2
The correct answer is option 2. 4
Octahedral voids (O-voids)
These voids are formed by overlapping of two trigonal voids of adjacent layers.
Surrounding spheres are located at the corners of an octahedron.
Coordination number = 6
In a unit cell of FCC type, octahedral void is located at body-center and at the edge centers of cubic unit cell.
Total number of O-voids per unit cell \(= \frac{1}{4} \times 12 + 1 \times 1 = 4\)