Molecular Dynamics Demonstration

A simple molecular dynamics model is constructed using the Lennard-Jones potential truncated at a distance of 3 molecular diameters. This is a reasonably accurate model of then interactions between noble gas atoms.  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.

You can select various initial configurations using the drop down menu.  These conditions are from Dan Schroeder with suggestions from John John Mallinckrodt.  See:  <http://physics.weber.edu/schroeder/software/>.

The statistics displayed at the top of the simulation are temperature, pressure, total energy, kinetic energy, potential energy (from interactions between molecules and interactions with the walls), and gravitational energy. Note that the temperature and pressure are computed from the average values and may not be accurate for short times or when there's organized motion on a large scale.

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The Molecular Dynamics Demonstration simulation is based on a Java applet written by Dan Schroeder, Physics Department, Weber State University.   See: <http://physics.weber.edu/schroeder/software/>

This simulation was created by Wolfgang Christian using the Easy Java Simulations (Ejs) modeling tool and is designed to teach modeling.  Users can inspect and modify the underlying model by copying the model from the running program into Ejs.  Right click within the simulation to examine the model in Ejs. 

You can examine and modify this simulation if you have Ejs installed by right-clicking within a plot and selecting "Open Ejs Model" from the pop-up menu. Information about Ejs is available at: <http://www.um.es/fem/Ejs/>.

The Easy Java Simulations (EJS) manual can be downloaded from the ComPADRE Open Source Physics collection and from the Ejs website.

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