Journal of Statistical Physics, Vol. 52, Nos. 5/6, 1988. p. 1413-1421.
In hard-sphere systems, there is a fluid-solid transition, but no gas-liquid transition. In the fluid region, however, one can find a purely geometric percolation transition, which is studied in detail. The van der Waals model of hard spheres is treated. In this model, a uniform negative background potential is added. This modification does not change the structure, but induces a gas-liquid transition. In fact, percolation and the gas-liquid transition can be related to each other.