Atomic Level Stresses in Solids and Liquids

Abstract

In condensed matter systems there are, in general, stresses at atomic level which are related to local incompatibilities. Only in perfect crystals in which all the atoms are equivalent such incompatibilities do not exist but they are present in ordered structures with non‐equivalent atoms and in any disordered structure. In this paper evaluation of these stresses in the framework of the local density functional approximation, embedded atom method, and central force interactions is first described. The usefulness and physical significance of this concept in the description of the local atomic structure of liquids and glasses is then demonstrated using as examples atomistic studies of microscopic processes involved in structural relaxation and glass transition. Finally, it is argued that the concept of atomic level stresses provides a general means for describing atomistics of complex structures, both, ordered and disordered.