In a hard-sphere model, packing fraction is N(4πr³/3)/a³. At contact, simple cubic fills 52.36%, BCC 68.02% and FCC 74.05%. Reducing the displayed radii leaves more empty space but does not change how many lattice sites belong to a cell.
In a hard-sphere model, packing fraction is N(4πr³/3)/a³. At contact, simple cubic fills 52.36%, BCC 68.02% and FCC 74.05%. Reducing the displayed radii leaves more empty space but does not change how many lattice sites belong to a cell.