Thermodynamic properties of a nonideal gas in a homogeneous gravitational field

The partition function for a nonideal gas in the gravitational field has been evaluated classically, assuming that the height of the system is rather small. The thermodynamic properties and the equation of state have been calculated for such a system and compared with the corresponding ones for the nonideal gas in the absence of the external field, as well as for the ideal gas in the gravitational field.