On the simulation of vapor–liquid equilibria for alkanes

Abstract

A Monte Carlo simulation study has been conducted to assess the ability of recently proposed force fields to predict orthobaric densities, second virial coefficients, and P-V-T data for short and long alkanes. A new, modified force field is proposed that provides good agreement with experimental phase equilibrium and second virial coefficient data over wide ranges of temperature and chain length.

Energy Landscape and Isotropic Tensile Strength of n-Alkane Glasses

“…In Table 1, it seems counterintuitive that a methyl group should be smaller than a methylene group, but this is actually consistent with other force fields designed for simulating n-alkanes. 67,72 Second, adjacent united atoms within the same chain overlap by virtue of specification of the equilibrium bond lengths. It has been shown that these are essential requirements in order for a united atom model to reproduce the maxima in critical pressure and density as a function of chain length.…”

“…Bond stretching and bending are described by harmonic potentials 67,68 Figure 1. Equation of state of the energy landscape for n-hexane.…”

Molecular Simulations of Zeolites: Adsorption, Diffusion, and Shape Selectivity

“…For the hydrocarbons, special force fields, both for united-atom and allatom models, have been developed that give an accurate description of the vapor-liquid coexistence curve over a wide range of conditions. 57,78,[80][81][82][83][84][85][86] Figure 12 gives a typical illustration of the accuracy that can be obtained with these types of models.…”

Optimized intermolecular potential for nitriles based on Anisotropic United Atoms model

“…Thus, the number of Van der Waals interactions sites for a given alkane equals its number of carbon atoms and the bead center is located at the carbon atom positions. Other successful UA potentials are the NERD potential [25] proposed by Nath et al in 1998 or the TraPPE family models [26] developed by Martin and Siepmann.…”