HTML_EDITOR Intro Page true true In solid state physics, a popular example of the interaction between noble gas atoms is the The Lennard Jones Potential . This interaction is clearly presented in "Introduction to Computer Simulation Methods: Applications to Physical Systems" by H. Gould and Jan Tobochnick 2nd edition as: V(r)=4*E*[(s/r)¹² - (s/r)⁶ ], with the force associated with this potential written as F(r)=24*E*[2*(s/r)¹² -(s/r)⁶] r, where E and s are the energy and distance parameter associated with this model.In the case of Argon, s=3.4x10^-10 meters, E=1.65x10^-12 Joules, m=6.69x10^-26 kg. However, in this calculation, we use units of e_b=1x10^-19 Joules, distance units of a_b=1x10^-10 meters, mass units of m_b=1e-26 kg; so that, the time units are a_b*(m_b/e_b)^1/2 . The simulation is done in one dimension. Finally, the simulation shows one atom fixed at the origin, another atoms sitting at an initial position. As the simulations is started, the molecules begin to interact as indecated by the motion of the right particle. The graph shown indicates the position of the moving particle as a function of time. Notice that the particle oscillates about an equilibrium point. This equilibrium point is actually the average distance between the particles known as the bond length. The simulation is capable of displaying the value of the particle's velocity as a function of time and the particle motion can be traced as well, all by checking the appropriate interactive bottons. ]]> 25 false VARIABLE_EDITOR Planet true true time double space double E double x double vx double s double m double double CODE_EDITOR Init true true ODE_EDITOR Orbit true true time 0.1 vx 24.0*E*(2.0*Math.pow(s/x,12)-Math.pow(s/x,6))/x/m RungeKutta true Elements.Frame mainFrame true mainFrame border true 553,275 true Elements.Panel panel mainFrame west border 90,0 true Elements.Panel panelButtons panel north grid:0,1,0,0 Elements.Button Play panelButtons Play _play() _isPaused Elements.Button Pause panelButtons Pause _pause() _isPlaying Elements.Button Initialize panelButtons Initialize _initialize() Elements.CheckBox Trace panelButtons Trace trace false Elements.CheckBox Velocity panelButtons Velocity velocity false Elements.CheckBox ShowPanel panelButtons Control showPanel false true Elements.Panel PanelControl panel south grid:0,1,0,0 showPanel Elements.Field Time PanelControl time time = 0.### Elements.Field Vx PanelControl vx Vx = 0.###;Vx = -0.### true Elements.DrawingPanel drawingPanel mainFrame center false false -space/2.0 space -space space Elements.Trace Trace drawingPanel 1500 x 0.0 true darkGray NO_MARKER trace Elements.Arrow Velocity drawingPanel x vx velocity 0.1 0.1 darkGray Elements.Particle Particle drawingPanel 0.0 0.0 1.0 1.0 false Elements.Particle Particle2 drawingPanel x 0 1.0 1.0 green Elements.Slider Space mainFrame south space 10 20 Space = 0.## 10 0.# true Elements.PlottingPanel PlottingPanel mainFrame east PlottingPanel true true Elements.Trace Trace2 PlottingPanel time x true NO_MARKER