The Ga-Nd binary system has been modeled using existing experimental data on phase equilibria and thermodynamic properties through the CALPHAD methodology. The Ga–Nd binary system contains six intermetallic compounds: \(\text{Ga}_{6}\text{Nd}\_\text{rt}\) , \({\text{G}\text{a}}_{6}\text{N}\text{d}\_\text{h}\text{t}\) , \(\:{\text{G}\text{a}}_{2}\text{N}\text{d}\) , \(\:\text{G}\text{a}\text{N}\text{d}\) , \(\:{\text{G}\text{a}}_{3}{\text{N}\text{d}}_{5}\) and \(\:{\text{G}\text{a}\text{N}\text{d}}_{3}\) . All these compounds were modeled as stoichiometric phases, except for the \(\text{Ga}_2\text{Nd}\) compound, which exhibits a homogeneity range. It was described using a two-sublattice model with substitution on one sublattice. In addition to the intermetallic compounds, this phase diagram also comprises a Ga-rich solid solution, two Nd-rich terminal solid solutions ( \(\text{Nd}\_\text{r}\text{t}\) and \(\text{Nd}\_\text{h}\text{t}\) ), and a liquid phase. The Gibbs energy of the liquid phase in the Ga–Nd binary system was modeled using the Redlich–Kister polynomial formalism, which describes deviations from ideal mixing. The temperature dependence of the interaction parameters was treated either as a linear function or using the exponential formulation proposed by Kaptay. The results obtained from the thermodynamic modeling show strong consistency with both the phase diagram data and the experimentally determined thermodynamic values reported in the literature. The thermodynamic parameters of the Ga–Nd binary system have been assessed for the first time, enabling the calculation of phase equilibria and thermodynamic properties for both the liquid phase and the intermetallic compounds.
