Criticality of charged systems. II. The binary mixture of hard spheres and ions

The pairing mean spherical approximation (PMSA) developed in the previous paper of this series is applied to a binary mixture of hard spheres and ions of the restricted primitive model. The resulting equation of state is used to investigate the phase equilibrium for the binary mixture. It is found that the model exhibits type‐III phase behavior. This work serves as the basis for more realistic models.