Simulation of Lennard-Jones interactions

A molecular dynamics simulation of molecules in two dimensions interacting via the Lennard-Jones potential. The output shows the velocity distribution.

Algorithm

The algorithm for simulating the evolution of the particles can be summarized by the following steps:

  1. Compute the forces on all the particles due to the other particles. By Newton's second law the acceleration of each particle is given by the total force on the particle divided by its mass which we set to unity.
  2. Use a numerical algorithm to update the positions and velocities of all the particles at a time t + Δt later. The program uses the Verlet algorithm.
  3. Accumulate data in the speed histogram.

Reference:

Gould and Tobochnik Statistic and Thermal Physics to be published by Princeton University Press (2010).  Draft chapters are available online at <http://stp.clarku.edu/>.

Note:

This simulation was created by Wolfgang Christian using the Easy Java Simulations (Ejs) modeling tool.  It is based on a Java program from the Statistical and Thermal Physics Project. You can modify this simulation if you have Ejs installed by right-clicking within a plot and selecting "Open Ejs Model" from the pop-up menu item. Information about Ejs is available at: <http://www.um.es/fem/Ejs/>.