Limitations of the Hayden-O'Connell equation of state

This equation of state provides a good approximation for systems at moderate densities. You should use this equation of state only for densities less than approximately one half of the critical density.

As a rough rule, this equation of state is valid for the following pressure range:

where

Pc,i is the critical pressure of component i

Tc,i is the critical temperature of component i

n is the total number of components in the system