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Lennard Jones- reduced units

  1. Feb 16, 2010 #1
    Hi friends,
    I have a question regarding MD simulation using a LJ potential. If I take the e and sigma parameters in the LJ potential to be that corresponding to argon, and calculate some thermodynamic
    quantity can I convert the value of that thermodynamic quantity corresponding to some other substance
    which might have a different e and sigma. This is because in MD simulation we use reduced units and there is something called the law of corresponding states which might enable one to convert that thermodynamic quantity for another substance without having to run a different simulation.

    Please help.

  2. jcsd
  3. Feb 16, 2010 #2
    Welcome to Physics Forums!
    Let's say that at certain temperature and density (T1, rho1)you calculate certain quantities for Ar. Then these quantities also belong to Xe at another temperatue and density (T2,rho2) and also belong to Kr at third T,rho and for all other materials decribed by Lennard Jones at Different T,rho.
    However, keep in mind that one simulation is equivalent to one state defined by T,rho. There is no direct way to extrapolate the results of one simulation to other states.
  4. Feb 17, 2010 #3
    thanks a lot for your help.

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