Structure, stresses, and local dynamics in glasses

The inter-relations between short-range structural and elastic aspects in glasses and glass forming liquids pose important and yet unresolved questions. They are relevant for understanding of the constraints on the glassy structure and the global vibrations. In this paper, these relations are analyzed for monoatomic glasses and liquids with a short-range repulsive-attractive pair potentials. Strong variations of the local pressure are found even in the zero temperature glass, whereas the largest values of pressure are the same in both glasses and liquids. New short-range structural-elastic relations appear when one considers the effects of local pressures on the radial distribution function, the position of its first peak, and the coordination number. Also, a structural similarity between liquids and glasses is manifested by similar dependencies of the coordination number on the local pressures. Linear relations were found between components of site stress tensor and the components of atomic force-constants matrix and also between the trace of the squares of the atomic eigenfrequencies and the local effective pressures. These relations hold both for glasses at zero temperature and for liquids. The linearity is explained by inter-relations between the local structure and potential terms.