Melting of metallic and intermetallic solids: An energetic view from DFT calculated potential wells

Potential wells of metallic and intermetallic phases are constructed by ab initio calculation using the density functional theory. The potential wells are presented as a function of a characteristic length scale equivalent to the cubic root of the average atomic volume, to reflect the importance of density on binding. The results show that the characteristics of a potential well dictates the melting temperature of a crystalline solid metal or an intermetallic phase. The energetic requirement for melting is equivalent to an activation state where the slope of the potential well gets close to the positive maximum, or where the well experiences a step change in energetic state. The work offers a way to predict melting points of metallic/intermetallic phases, which is particularly useful to metastable phases, for which it is usually difficult to measure the melting points directly. Such predicted data on melting points are useful for establishing thermodynamic databases for phase diagram calculations.