This investigation attributes the physical significance of the excess thermodynamic functions to their aesthetic ability in the domain of thermofunctions. Excess functions are discovered superior particularly in revealing the molecular interactions of binary condensed interphase molecules, since they provide the quantitative idea of deviations occurring in the experimental observations while exploring the solidus-liquidus phase equilibrium curves of binary transparent and opaque eutectic systems. These functions not only explain the miscibility criteria but also their physical behaviour at the condensed eutectic composition in view of Planck’s theoretical concept of temperature independent entropy resulting in from the Weibull distribution of interphase molecules ensuring the complete stability of binary system at this very composition. The concept implicitly discusses the descending and ascending order in values of excess Gibbs free energy (GE) and excess entropy (SE) of mixing along either side of the solidus-liquidus equilibrium curve furnishing the eutectic composition accomplished with GE minimum and SE maximum followed by excess enthalpy of mixing, HE. Moreover, excess functions are found capable of providing an alternative theoretical procedure to study the phase equilibria particularly of binary eutectic systems disseminating their physical understanding comprehensively. Guggenheim lattice theory offers supporting evidence to the aesthetic ability of excess functions harbingering the existence of molecular interactions in the binary condensed eutectic systems.
