This script is an implementation of Molecular Dynamics simulation for a set of atoms of one kind with van der Waals interactions - noble gas model. Simulating this in Jmol will show phase transition from solid crystal to gas. Initial conditions are N atoms described with $r_i = (x_i, y_i, z_i)$ position coordinates and momentum $p_i$. Position coordinates are calculated from elementary cell vectors of the crystal. Initial momenta have Maxwell's distribution. Each couple of atoms interacts with van der Waals forces $V^P$ and with limited area of a sphere $V^S$.

Output file can be animated using Jmol applet. Jmol animation: