Microscopic variational lattice liquid cluster model for ionic correlations inα−AgI

A mean-field model for mobile ion configurations in $\alpha -\mathrm{A}\mathrm{g}\mathrm{I}$ is proposed that permits the first simultaneous calculation of the site-disorder entropy and the ion diffusion activation energy. The model uses only one adjustable parameter, the mobile-ion effective charge, and it is in very good agreement with experiment. It shows that the mobile ions should be regarded as a lattice liquid and not a lattice gas.