W0128

Computer Simulation Studies of Polyamorphism . Peter H. Poole, Department of Applied Mathematics, University of Western Ontario, London, Ontario, N6A 5B7, Canada

We review recent computer simulation studies in which polyamorphism has been explicitly observed. Defined simply as the observation of multiple but distinct amorphous solid forms of the same substance, polyamorphism has been found most prominently in simulations of amorphous solid silicon, silica, and water. The most dramatic form of polyamorphism, in which an equilibrium first-order liquid-liquid phase separation occurs above the glass transition temperature has also been found in simulations of silicon and water models. The thermodynamic and structural indicators of polyamorphism are thereby revealed in detail in such simulation studies. We will also point out correlations between the properties of polyamorphic glasses and the crystal polymorphs found for the same materials.