Structure, Stresses and Local Dynamics in Glasses

TL;DR

This paper investigates the relationship between local structure, stresses, and elastic properties in glasses and liquids with short-range interactions, revealing consistent pressure-related correlations across phases.

Contribution

It uncovers linear relations between local stresses, elastic constants, and structural parameters in mono-atomic glasses and liquids, highlighting structural similarities.

Findings

Local pressure varies significantly even in zero-temperature glasses.

Coordination number depends on local pressures in both glasses and liquids.

Linear relations exist between site stress components, elastic constants, and local frequencies.

Abstract

The interrelations between short range structural and elastic aspects in glasses and glass forming liquids pose important and yet unresolved questions. In this paper these relations are analyzed for mono-atomic glasses and stressed liquids with a short range repulsive-attractive pair potentials. Strong variations of the local pressure are found even in a zero temperature glass, whereas the largest values of pressure are the same in both glasses and liquids. The coordination number z(J) and the effective first peak radius depend on the local pressures J's. A linear relation was found between components of site stress tensor and the local elastic constants. A linear relation was also found between the trace of the squares of the local frequencies and the local pressures. Those relations hold for glasses at zero temperature and for liquids. We explain this by a relation between the structure and the potential terms. A structural similarity between liquids and solids is manifested by similar dependencies of the coordination number on the pressures.