Spinodal and the melting curve of a Lennard-Jones crystal at negative pressure

Abstract

Two macroscopic phases that are instable with respect to the formation of a certain third phase in them may coexist in equilibrium [1, 2]. Thus, the fluid–crystal phase equilibrium line must have an analytic continuation to the negative-pressure region. At pressures below the triple point, both a fluid that is overcooled beyond this line and a crystal that is overheated beyond this line are doubly metastable. The positions of the melting curve and spinodals of the fluid and crystal on the thermodynamic surface of state and their low-temperature asymptotic behaviors are of interest. In this work, these problems are solved using the molecular dynamic method.