The Lennard-Jones potential corresponds to the special case where n = 12 and m = 6 in Eq. (1). In Eq. (1), ε ε is the dispersion energy, and σ σ indicates the distance at which V = 0 , which is sometimes called the "collision radius." The parameter σ σ is generally indicative of the size of the particles involved in the collision. The parameters n and m characterize the shape of the potential: n describes the character of the repulsion and m describes the character of the attraction.