Density effects in a bulk binary Lennard-Jones system

TL;DR

This study investigates how density influences the properties of local minima in a binary Lennard-Jones system across different temperatures, revealing a limiting density below which structural properties remain unchanged.

Contribution

It identifies a limiting density in a binary Lennard-Jones system and analyzes how local minima properties depend on density and temperature.

Findings

A limiting density at =1.06 with negative pressure.

Structural properties are similar below the limiting density.

Energy, pressure, and mode frequencies are temperature-independent below =1.06.

Abstract

Properties of local minima as a function of density are studied in a binary Lennard-Jones system for kinetic equipartition temperatures $T=1.0$ (normal liquid), 0.5 (supercooled liquid), and 0.4 (glass), in reduced units. The number of different local minima sampled, energy, pressure, normal mode angular frequencies, mean distance between all pairs of local minima and partial radial distribution functions are presented. In agreement with previous studies by Sastry [Phys. Rev. Lett. {\bf 85}, 590 (2000)] a limiting density is found at $\rho_l=1.06$ with negative pressure, below which the local structure of the glass and the supercooled phases are essentially the same, as evidenced by the partial radial distribution functions. The mean energy, pressure, and normal mode frequencies have values that are practically independent of the temperature below $\rho_l$.