Final answer:
To calculate bcc tetrahedral interstitial sites, locate the midpoints of the edges of the cube and connect them, creating a tetrahedron. In a BCC structure, each unit cell contains one octahedral hole and one tetrahedral hole. The number of tetrahedral interstitial sites is half the number of atoms per unit cell.
Step-by-step explanation:
Tetrahedral interstitial sites can be calculated in a body-centered cubic (BCC) structure. In a BCC lattice, each unit cell contains one octahedral hole and one tetrahedral hole. The tetrahedral hole is formed by locating the midpoints of the edges of the cube and connecting them, which creates a tetrahedron. The number of tetrahedral interstitial sites in a BCC structure is half the number of atoms per unit cell.