van der Waals equation

Etymology
Named after Dutch physicist.

Proper noun

 * 1)  A gas law which generalizes the ideal gas law to non-ideal gases, taking into account intermolecular forces and the size of molecules.
 * $$(P+\frac{a}{V^2})(V-b)=RT$$, where $$a$$ and $$b$$ are constants experimentally determined for a particular gas.