On putting more physics into calphad solution models

A useful dialogue between those involved in the ‘ab initio’ calculation of phase diagrams and the CALPHAD community is being impeded by the solution models currently used in free energy minimisation packages. The present paper discusses a versatile solution model, incorporating more physics than in current models. It is suitable for incorporating calculated parameters as they become available but can also be used empirically as will usually be necessary for obtaining the required degree of accuracy in phase diagram calculations for multicomponent systems. The model, applicable to alloys, semiconductors, electroceramics and ionic systems, is being incorporated into the ChemSage software package.