Universality of melting and freezing indicators and additivity of melting curves

The assumption of universality of some melting and freezing indicators, in the context of approximate models of the liquid and the solid, gives rise to simple semi-empirical melting equations that describe additivity of melting curves. The melting equations are exact in the high temperature limit and give reasonably accurate results also near the triple point. They find many applications including quantum corrections to the melting curve.