Thermostatting via Wall Collisions

• Wall collision imparts random velocity to molecule

  • selection consistent with (canonical-ensemble) Maxwell-Boltzmann distribution at desired temperature
  • click here to see an applet that uses this thermostat

• Advantages

  • realistic model of actual process of heat transfer
  • correctly samples canonical ensemble

• Disadvantages

  • can’t use periodic boundaries
  • wall may give rise to unacceptable finite-size effects
    not a problem if desiring to simulate a system in confined space
    
  • not well suited for soft potentials

random p

Gaussian

Wall can be made as realistic as desired

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