Phase diagram of the modified Lennard-Jones system

Abstract

An investigation of the precise determination of melting temperature in the modified Lennard-Jones system under pressure-free conditions [Y. Asano and K. Fuchizaki, J. Phys. Soc. Jpn. 78, 055002 (2009)] was extended under finite-pressure conditions to obtain the phase diagram. The temperature and pressure of the triple point were estimated to be 0.61 ε∕k(B) and 0.0018(5) ε∕σ(3), and those of the critical point were 1.0709(19) ε∕k(B) and 0.1228(20) ε∕σ(3), where ε and σ are the Lennard-Jones parameters for energy and length scales, respectively, and k(B) is the Boltzmann constant. The potential used here has a finite attractive tail and does not suffer from cutoff problems. The potential can thus be a useful standard in examining statistical-mechanical problems in which different treatments for the tail would lead to different conclusions. The present phase diagram will then be a useful guide not only for equilibrium calculations but also for nonequilibrium problems such as discussions of the limits of phase (in)stability.

Sublimation of the Modified Lennard-Jones System

“…2) The former and the latter were estimated to be located at T t ¼ 0:61 and p t ¼ 0:0018ð5Þ, and at T c ¼ 1:0709ð19Þ and p c ¼ 0:1228ð20Þ, respectively. 3) Here, we chose among possible variations the type of potential tail cutoff introduced in Ref.…”

“…2) In contrast to the condensed phases, the Gibbs free energy per particle, g g , of the gas phase was evaluated only approximately from the virial expansion at the lowest order. The expansion requires a density, , as input information.…”

“…Throughout the simulations, N ¼ 6912 particles were employed in the mLJ system to eliminate the finite-size effects as much as possible. 2) Other numerical details as well as the method of the MD simulation were the same as described in Ref. 2.…”

Multistage structural evolution in simple monatomic supercritical fluids: Superstable tetrahedral local order

“…The system was studied in the density region of ρ ∈ (0.32−1.0) at temperatures up to T = 100 (that is much higher than the melting line and the critical temperature). According to equilibrium temperature-density phase diagram [28][29][30][31][32][33][34][35][36][37][38], this range completely includes the area corresponding to liquid phase and widely covers the region of fluid state.…”

Lennard-Jones systems near solid walls: Computing interfacial free energies from molecular simulation methods

“…(1), the value for γ cl is also needed. Therefore, we carried out simulations using a form of the LJ potential first introduced by Broughton and Gilmer [39,[43][44][45][46], for which γ cl has already been determined using the "cleaving potential" approach [44] as well as the Gibbs Cahn integration technique [39].…”