A procedure is described for the gradual modification by computer of the topology of hand-built models of tetrahedrally coordinated amorphous semiconductors. Starting from a model which had no odd-membered rings, we generated a series of structures with increasing numbers of five-membered rings, and increasing distortion in bond angle. The best fit to the experimentally determined radial distribution function of amorphous germanium was obtained with a model having an average of 0.336 five-membered rings per atom and an rms bond angle distortion of 11.6°.

• Received 29 April 1975

DOI:https://doi.org/10.1103/PhysRevB.12.1399