Canonical ensemble
Variables:
- Number of Particles,
- Volume,
- Temperature,
Partition Function
Classical Partition Function (one-component system) in a three-dimensional space:
where:
- is the de Broglie wavelength (depends on the temperature)
- , with being the Boltzmann constant
- is the potential energy, which depends on the coordinates of the particles (and on the interaction model)
- represent the 3N position coordinates of the particles (reduced with the system size): i.e.
Free energy and Partition Function
The Helmholtz energy function is related to the canonical partition function via: