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Accurate Determination of the Equilibrium Surface Tension Values with Area Perturbation Tests
Published on: August 30, 2019
Evaluation of the pressure tensor and surface tension for molecular fluids with discontinuous potentials using the
Guadalupe Jiménez-Serratos1, Carlos Vega, Alejandro Gil-Villegas
1Departamento de Ingeniería Física, División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato, Colonia Lomas del Campestre, León 37150, Mexico.
Abstract:
In this article we apply the volume-perturbation method to systems of particles interacting via discontinuous potentials. We have found that an accurate Monte Carlo simulation protocol can be used in order to study properties of very general non-spherical systems with discontinuous potentials, such as chain molecules and spherocylinders with square-well interactions, and chain molecules with square-well and square-shoulder interactions. From the simulation results obtained for these systems we verify that: (1) the method reproduces the pressure as used in NPT simulations; (2) discontinuous infinite repulsive interactions give asymmetric contributions to the pressure when compression and expansion movements are used; however for finite interactions these contributions are symmetric; and (3) the pressure contributions preserve the additivity of the potential interactions. Density profiles and surface tension for subcritical conditions are accurately predicted.
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