Lennard-Jones (LJ) model
In this Molecular Dynamics exercise we mainly are concentrating on Lennard-Jones model. LJ is a model with forces that are strongly repulsive at very short interparticle distances, attractive forces at large distances, and weak attractive forces at very large distance. These forces are confirmed by looking at the slope on the potential for the LJ model shown below. Notice that unlike the energy potential for the HL model the potential for the LJ model goes to zero at large distances. This allows for interatomic bonds to break permanently when atoms are seperated by large distances. Hence we can model "slip" along interatomic planes or the transformation of a solid to liquid when the particle motion (atom velocity ) increases with increasing kinetic energy.
For a more complete explanation of the LJ model read "Molecular Dynamics: An Introduction" by Lloyd Fosdick.