Spherically averaged versus angle-dependent interactions in quadrupolar fluids

dc.creatorMognetti, Bortolo Matteo
dc.creatorOettel, Martin
dc.creatorYelash, Leonid
dc.creatorVirnau, Peter
dc.creatorPaul, Wolfgang
dc.creatorBinder, Kurt
dc.date2008-03-25
dc.date.accessioned2026-07-07T09:33:06Z
dc.date.available2026-07-07T09:33:06Z
dc.descriptionEmploying simplified models in computer simulation is on the one hand often enforced by computer time limitations but on the other hand it offers insights into the molecular properties determining a given physical phenomenon. We employ this strategy to the determination of the phase behaviour of quadrupolar fluids, where we study the influence of omitting angular degrees of freedom of molecules via an effective spherically symmetric potential obtained from a perturbative expansion. Comparing the liquid-vapor coexistence curve, vapor pressure at coexistence, interfacial tension between the coexisting phases, etc., as obtained from both the models with the full quadrupolar interactions and the (approximate) isotropic interactions, we find discrepancies in the critical region to be typically (such as in the case of carbon dioxide) of the order of 4%. However, when the Lennard-Jones parameters are rescaled such that critical temperatures and critical densities of both models coincide with the experimental results, almost perfect agreement between the above-mentioned properties of both models is obtained. This result justifies the use of isotropic quadrupolar potentials. We present also a detailed comparison of our simulations with a combined integral equation/density functional approach and show that the latter provides an accurate description except for the vicinity of the critical point.
dc.descriptionPhys. Rev. E, accepted
dc.identifierhttps://arxiv.org/abs/0803.3507
dc.identifierhttp://arxiv.org/abs/0803.3507
dc.identifierPhys. Rev. E 77, 041506 (2008)
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/159017
dc.subjectStatistical Mechanics
dc.titleSpherically averaged versus angle-dependent interactions in quadrupolar fluids
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