Optimization of thermodynamic and phase diagram data has been performed and
consistent sets of coefficients for the calculation of the phase equilibri
a in the system Ni-Zn have been obtained using the program BINGSS. The delt
a phase has been modeled as a stoichiometric compound (NiZn8). The binary l
iquid and the solid Ni-based solutions have been treated as disordered subs
titutional phases. The intermediate beta, beta(1), and gamma compounds have
been modeled as phases with substitutional defects and vacancies on two su
blattices. The calculated phase diagram and thermodynamic quantities are in
excellent agreement with the experimental data.