A MONTE-CARLO STUDY OF THE DIELECTRIC-CONSTANT OF THE RESTRICTED PRIMITIVE MODEL OF ELECTROLYTES ON THE VAPOR BRANCH OF THE COEXISTENCE LINE

We compute the wave number dependent dielectric constant ε(k) of the restricted primitive model of electrolytes along two isochores crossing the vapor branch of the coexistence curve. It is shown that, at low k, ε(k) is given by a Debye Hückel type law and therefore that ε-1(k) →0 as k→0. We conclude that the saturated vapor is conducting and that an insulator-conductor transition is unlikely. Earlier contradictory results by ourselves [J. Chem. Phys. 100, 2161 (1994)] are easily explained as a consequence of finite size effects. © 1995 American Institute of Physics.