atomic packing fraction of diamond cubic lattice is in percent
Answers
Answer:
Packing fraction = (N atoms) x (V atom) / V unit cell
N atoms is the number of atoms in a unit cell. V atom is the volume of the atom, and V unit cell is the volume of a unit cell.
Substitute the number of atoms per unit cell into the equation. Diamond has eight atoms per unit cell, so the diamond packing fraction equation now becomes:
Packing fraction = 8 x (V atom) / V unit cell
Substitute the volume of the atom into the equation. Assuming atoms are spherical, the volume is: V = 4/3 × π × r3
The equation for packing fraction now becomes:
Packing fraction = 8 x 4/3 × π × r3/ V unit cell
Substitute the value for the unit cell volume. Since the unit cell is cubic, the volume is V unit cell = a3
The formula for packing fraction then becomes:
Packing fraction = 8 x 4/3 × π × r3/ a3
The radius of an atom r is equal to √3 x a/8
The equation is then simplified to : √3 x π/16 = 0.3401