Keywords

Molecular dynamics, Monte Carlo methods, Phase transitions, Thermal instruments, Thermodynamic states and processes, Programming languages, Voronoi diagrams, Crystal structure, Intermolecular forces, Organic compounds

Abstract

Molecular dynamics simulations were performed to determine two-phase configurations of model propane molecules below the critical point and in the near-critical, two-phase region. A postprocessor that uses a Monte Carlo method for determination of volumes attributable to each molecule was used to obtain density histograms of the particles from which the bulk coexisting equilibrium vapor and liquid densities were determined. This method of analyzing coexisting densities in a two-phase simulation is straightforward and can be easily implemented for complex, multisite models. Various degrees of internal flexibility in the propane models have little effect on the coexisting densities at temperatures 40 K or more below the critical point, but internal flexibility (angle bending and bond vibrations) does affect the saturated liquid densities in the near-critical region, changing the critical temperature by approximately 20 K. Shorter cutoffs were also found to affect the phase dome and the location of the critical point.

Original Publication Citation

Sonal Patel, W. Vincent Wilding, Richard L. Rowley; The use of two-phase molecular dynamics simulations to determine the phase behavior and critical point of propane molecular models. J. Chem. Phys. 14 January 2011; 134 (2): 024101. https://doi.org/10.1063/1.3528117

Document Type

Peer-Reviewed Article

Publication Date

2011-01-10

Publisher

American Institute of Physics

Language

English

College

Ira A. Fulton College of Engineering

Department

Chemical Engineering

University Standing at Time of Publication

Full Professor

Download

Share

COinS