The thermodynamic properties and phase diagram of the system Bi-Zn were opt
imized using Lukas' program BINGSS. Special efforts (including the pre-opti
mization treatment of data) were employed to reproduce the known flat, asym
metric, and convex shape of the miscibility gap. A comparison of calculated
values with their experimental counterparts is given. The basic statistica
l characteristics of the solution obtained are presented. Previous assessme
nts of the system are analyzed and compared with the present endeavor.