Coomber's relationship can be used to describe how the internal pressure and dielectric constant of a non-polar liquid are related.
As , which defines the internal pressure of a liquid, it can be found that:
where
* is equal to the number of molecules
* is the ionization potential of the liquid
* is a temperature dependent relation based on numerical constants of the pair summation from inter-particle geometry
* is the polarizability
* is the volume of the liquid
where for most non-polar liquids