title: Equation of state and liquid-vapor equilibrium of polarizable Stockmayer fluids.
abstract: In this work we develop the concept of an effective potential to obtain the equation of state of polarizable Stockmayer (PSM) fluids. This potential consists of a Lennard-Jones function with appropriate energy and distance parameters that depend on the reduced dipolar moment μ(∗) and polarizability α(∗). The approach deals accurately with polarizable SM fluids with μ(∗)≤2.0 and α(∗)≤0.1. However, prediction of second virial coefficients is reliable up to μ(∗)≤4.0. When the low-density sphericalized potential is used at moderate and large densities, the effect of the dipole-dipole attraction is overestimated in agreement with an effect previously found in the literature. This effect can be traced back to a frustration mechanism due to the interaction between three and more dipoles. We propose a model to account for this frustration effect and are able to reproduce the vapor-liquid equilibrium of polarizable SM fluids in agreement with simulated results from the literature. Molecular dynamics simulations were carried out to show that the effective SM fluid has a radial distribution function very close to that of the true SM system.
authors.affiliation: Departamento de Física, Universidad Autónoma Metropolitana, Iztapalapa, Apdo 55 534, México DF 09340, México. arirocich@yahoo.com.mx
authors.forename: Adrián
authors.initials: A
authors.lastname: Rocha-Ichante
authors.forename: Fernando
authors.initials: F
authors.lastname: del Río
authors.forename: Edgar
authors.initials: E
authors.lastname: Ávalos