What is packing efficiency? Calculate the packing efficiency in body-centred cubic crystals.
As the name suggests, packing efficiency is the proportion of the crystal (or unit cell) that is actually taken up by the atoms themselves. Packing efficiency is calculated by: Packing efficiency=Volume occupied by the atoms in the unit cellTotal volume of the unit cell x 100Packing efficiency=Volume occupied by the atoms in the unit cellTotal volume of the unit cell x 100 For BCC (Body centered cubic cell), volume occupied by the atoms in the unit cell is: 83 π r383 π r3 Total volume of the BCC unit cell is: 64r333–√64r333 Now, putting the values: Packing efficiency=83 π r3/64r3/3√3–√ x 100= 68
