Properties of a bound ensemble of repelling atoms

Abstract

Various data are combined to analyze the behavior of condensed rare gases at high pressures or systems of repelling atoms interacting via a pair interaction. An analysis based on numbers of nearest neighbors of a test atom shows that the crystalline state is not the most stable thermodynamically for a system of repelling atoms at high pressures. Rather, the equilibrium solid state of this system at nonzero temperature is an irregular mixture of small domains/clusters of fairly rigid, close-packed structures. This means that an ensemble of repelling atoms has a polycrystalline structure at high pressures and low temperatures. Parameters of this system at low temperatures and its melting curve are considered from different standpoints.