Isothermal-isobaric ensemble: Difference between revisions

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The classical partition function, for a one-component atomic system in 3-dimensional space, is given by
The classical partition function, for a one-component atomic system in 3-dimensional space, is given by


<math> Q_{NpT} = \frac{1}{\Lambda^3} \int_{0}^{\infty} d V  V^{N} \exp \left[ - \beta p V \right] \int d ( R^{3N} ) \exp \left[ - \beta U \left(V,(R)^{3N} \right) \right]
<math> Q_{NpT} = \frac{\beta p}{\Lambda^3 N!} \int_{0}^{\infty} d V  V^{N} \exp \left[ - \beta p V \right] \int d ( R^*)^{3N} \exp \left[ - \beta U \left(V,(R^*)^{3N} \right) \right]
</math>
</math>


where
where
:<math> \beta = \frac{1}{k_B T} </math>
*<math> \beta = \frac{1}{k_B T} </math>;
 
*<math> \left( R^* \right)^{3N} </math> represent the reduced position coordinates of the particles; i.e. <math> \int d ( R^*)^{3N}  = 1 </math>





Revision as of 21:06, 23 February 2007

Variables:

  • N (Number of particles)
  • p (Pressure)
  • T (Temperature)

The classical partition function, for a one-component atomic system in 3-dimensional space, is given by

where

  • ;
  • represent the reduced position coordinates of the particles; i.e.


References

  1. D. Frenkel and B. Smit, "Understanding Molecular Simulation: From Alogrithms to Applications", Academic Press