Liquid stability in a model for ortho-terphenyl

TL;DR

This study explores the phase diagram and stability limits of a simple model for ortho-terphenyl, including liquid-gas nucleation, spinodal, and energy landscape analysis, extending previous research to broader conditions.

Contribution

It provides new data on the phase diagram, estimates nucleation and spinodal lines, and analyzes the energy landscape's statistical properties across different volumes.

Findings

Identified the liquid-gas nucleation line and spinodal locus.

Found the energy landscape minima follow a Gaussian distribution.

Determined the volume dependence of landscape parameters.

Abstract

We report an extensive study of the phase diagram of a simple model for ortho-terphenyl, focusing on the limits of stability of the liquid state. Reported data extend previous studies of the same model to both lower and higher densities and to higher temperatures. We estimate the location of the homogeneous liquid-gas nucleation line and of the spinodal locus. Within the potential energy landscape formalism, we calculate the distributions of depth, number, and shape of the potential energy minima and show that the statistical properties of the landscape are consistent with a Gaussian distribution of minima over a wide range of volumes. We report the volume dependence of the parameters entering in the Gaussian distribution (amplitude, average energy, variance). We finally evaluate the locus where the configurational entropy vanishes, the so-called Kauzmann line, and discuss the relative location of the spinodal and Kauzmann loci.