An explicit expression for the static structure factor for a multi-Yukawa fluid: the one-component case

• Published in: Physics and chemistry of liquids 2016-09, Vol.54 (5), p.632-646
• Main Authors: Vázquez-Rodríguez, Ó., Ruiz-Estrada, H.
• Format: Article
• Language: English
• Subjects: Approximation; Closures; Computer simulation; Demand; Economic models; intermediate range order (IRO) structure; Liquids; Mathematical analysis; mean spherical approximation (MSA); Monte Carlo simulation; Multi-Yukawa fluid; Nonlinear equations; potential short-range attraction and long-range repulsion; Radial distribution; radial distribution function; static structure factor; Structure factor
• ISSN: 0031-9104; 1029-0451
• DOI: 10.1080/00319104.2016.1139708

By using the mean spherical approximation, we obtain an analytical expression for the static structure factor (SSF) for a monodisperse system of particles interacting through a potential given by a hard-sphere contribution and M Yukawa terms. This expression depends on scaling matrix Γ, which is determined by solving a set of nonlinear equations. Our theoretical results show that using three Yukawa terms in the closure relation greatly improves the accuracy when compared with hypernetted-chain closure and Monte Carlo simulation data, which display a secondary low-k peak in the SSF, due to the formation of an intermediate range order structure governed by a short-range attraction and a long-range repulsion. We discuss the appearance of such a peak in terms of the microstructure order given by the radial distribution function. Following the original proposal made by Waisman (Mol Phys. 1973; 25:45-48), we give an explicit expression that improves the structural properties of a hard-sphere system.