Vibrational States of Cluster-Bethe Lattice Models

The vibrational densities-of-states of models of disordered materials have been calculated using a Green's function method.

A cluster-chain model reproduces the density-of-states of an infinite mass-disordered chain of harmonically bonded particles.

A three-co-ordinated cluster-Bethe-lattice model has been developed to approximate the vibrational behaviour of alloys of three-co-ordinated particles, and cluster models investigating some aspects of bond angle variation and variable bonding co-ordination are also described.