The EJS Molecular Dynamics Exploration JavaScript Model shows the dynamics of simple atoms and molecules in a two-dimensional container. The force between the atoms is weakly attractive at short distances, but strongly repulsive when they touch. Use the simulation to explore phases of matter, emergent behavior, irreversibility, and thermal effects at the nanoscale.

Use the "Presets" drop down menu at the top of this simulation to explore pre-defined configurations.

The motion of the molecules is governed by Newton's laws, approximated using the Verlet algorithm with the indicated Time step. For sufficiently small time steps dt, the system's total energy should be approximately conserved. Users can select various initial configurations using the drop down menu.

The Molecular Dynamics Exploration was developed by Wolfgang Christian at Davidson College using the Easy Java/JavaScript Simulation  (EjsS) modeling and authoring tool created by Francisco Esquembre.  This EjsS simulation is based on a pure JavaScript + HTML 5 simulation developed by Daniel V. Schroeder, Physics Department, Weber State University. Although EjsS is a Java program, it can create stand alone JavaScript programs that run in almost any PC or tablet.