"Cluster—Bethe-lattice" method: The electronic density of states of heteropolar systems

The "cluster—Bethe-lattice" method is extended to the study of heteropolar systems. The Bethe lattice is solved for binary compounds of arbitrary coordination using simple tight-binding models. In particular systems with tetrahedral coordination, such as the zinc-blende, BC-8, and random-network structures are examined in detail. The results are compared with recent experimental photoemission data on the amorphous phases of binary compounds and interpreted in terms of topology.