Isothermal-isobaric ensemble

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

$Q_{NpT}=\frac{1}{{\mathrm{\Lambda }}^3}\underset{0}{\overset{\mathrm{\infty }}{\int }}dV{V}^N\exp [-\beta pV]\int d(R^{3N})\exp [-\beta U(V,(R{)}^{3N})]$

where

$\beta =\frac{1}{k_{B}T}$

References

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