Tight-binding approach to the electronic properties of ionic and covalent liquids

In this paper we present results of two tight-binding models and apply these to compound-forming alloys. The CPA model including electron-phonon coupling describes well the resistivity and other electronic properties of systems with a compound-forming composition satisfying the usual valence rules; i.e. based on charge transfer. The second model uses a Modified Bethe lattice to describe the atomic structure. It applies to covalently bonded clusters of like atoms in the condensed phase. Stability of clustering with respect to no clustering is discussed