Conclusion
Physical constants of pure fluids: estimation methods

We have presented the most commonly used methods for calculating the critical coordinates of pure bodies.

Generally speaking, the two most accurate functional group contribution methods for estimating the critical coordinates of organic substances are the Ambrose and Somayajulu methods, but they are difficult to use.

The more recent Somayajulu method is also more general. It can therefore predict the critical coordinates of a larger number of compounds, and even those of some inorganic compounds. Vetere's analytical method gives comparable accuracy for certain series of compounds. Many organic substances decompose at high temperatures, i.e. below their critical temperature. Knowledge of their critical constants is therefore particularly useful for calculating the critical constants of the mixtures of which they are components. In this case,...