33 Si Program in two parts: • The first one is devoted to ternary phase diagram and their use for synthesis of materials and especially crystal growth. The different kind of sections (isothermal and isoplethic) as well as projections are detailed. • The second part deals with computational thermodynamic. First, the principles of Calphad method are shortly introduced: modeling of thermodynamic functions using experimental data and constitution of databases. Next, the use of databases with ThermoCalc software to illustrate the use of computational thermodynamic as a support for materials synthesis and development