Packing fraction

For the hard sphere fluid

$\eta ={\frac {\pi }{6}}{\frac {N\sigma ^{3}}{V}}$

where $\sigma$ is the hard sphere diameter.

References

Related reading

• Elizabeth R. Chen, Daphne Klotsa, Michael Engel, Pablo F. Damasceno, and Sharon C. Glotzer "Complexity in Surfaces of Densest Packings for Families of Polyhedra", Physical Review X 4 011024 (2014)