Abstract:A system of semi empirical equations has been tested by data fitting using a new computation technique-genetic algorithms. These equations have been developed for the analysis of the thermodynamic properties of some liquid alloys with strong interacted components such as Na Tl and Na Sn. The equations, which are based on the quasichemical model, take into account the dependence of the interaction energy on the microscopic environments. The enthalpy of mixing composition curves can be rather accurately described by this modified Guggenheim's formula, but the experimental data of the entropy of mixing are in discrepancy with the calculated configurational entropy of mixing. This discrepancy can be explained by nonconfigurational entropy change due to stronger chemical bond formation.

Key words: genetic algorithms thermodynamic properties quasichemical model Na Tl alloys Na Sn alloys