Coomber's relationship

Coomber's relationship can be used to describe how the internal pressure and dielectric constant of a non-polar liquid are related.

As p_i=\left(\frac{\partial E}{\partial V}\right)_T\,, which defines the internal pressure of a liquid, it can be found that:

p_i=n\cdot{I}\cdot{b(T)}\frac{N^2\alpha^2}{V^{n+1}}\,

where N\, is equal to the number of molecules

I\, is the ionization potential of the liquid

b(T)\, is a temperature dependent relation based on numerical constants of the pair summation from inter-particle geometry

\alpha\, is the polarizability

V\, is the volume of the liquid

where for most non-polar liquids n=1\,

References