Miedema's model is a semi-empirical approach for estimating the heat of formation of solid or liquid metal alloys and compounds in the framework of thermodynamic calculations for metals and minerals. It was developed by the Dutch scientist Andries Rinse Miedema while working at Philips Natuurkundig Laboratorium. It may provide or confirm basic enthalpy data needed for the calculation of phase diagrams of metals, via CALPHAD or ab initio quantum chemistry methods. For a binary system composed by elements A and B, a generic Miedema Formula could be cast as where terms and are explained and reported below. For a binary system the physical picture could be simplified by considering a relatively simpler function of the difference of these three physical parameters resulting in a more complex form: .