The thermodynamic properties of interstitial solute atoms in a solvent matrix were derived in terms of this model. The results were relevant to low temperatures, where the solute distribution was governed by Fermi-Dirac statistics rather than by the Boltzmann distribution which was typically used in the high-temperature limit. It was found that the modelled thermodynamic functions exhibited singularities which were related to the successive occupation of cells with a given energy level.

P.Maroevic, R.B.McLellan: Journal of the Physics and Chemistry of Solids, 1997, 58[3], 403-12