Canonical free energy is minus the logarithm of a fixed-particle-number partition function divided by inverse temperature. For classical particles in a cube 
of volume 
, with pair energy 
and position measure independent of 
, use
 |
At density 
,
its thermodynamic free-energy density is
 |
when the limit exists, where 
is the floor function.
The cubes have free boundary conditions and no temperature-dependent factor is included
in the position measure.
