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Local Structure and Thermodynamics of a Core‐Softened Potential Fluid: Theory and Simulation
Author(s) -
Zhou Shiqi,
Jamnik Andrej,
Wolfe Elie,
Buldyrev Sergey V.
Publication year - 2007
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200600516
Subject(s) - statistical physics , monte carlo method , molecular dynamics , grand canonical ensemble , work (physics) , homogeneous , perturbation theory (quantum mechanics) , core model , physics , canonical ensemble , ornstein–zernike equation , thermodynamics , integral equation , mathematics , quantum mechanics , mathematical analysis , statistics
Phase behavior and structural properties of homogeneous and inhomogeneous core‐softened (CS) fluid consisting of particles interacting via the potential, which combines the hard‐core repulsion and double attractive well interaction, are investigated. The vapour–liquid coexistence curves and critical points for various interaction ranges of the potential are determined by discrete molecular dynamics simulations to provide guidance for the choice of the bulk density and potential parameters for the study of homogeneous and inhomogeneous structures. Spatial correlations in the homogeneous CS system are studied by the Ornstein‐Zernike integral equation in combination with the modified hypernetted chain (MHNC) approximation. The local structure of CS fluid subjected to diverse external fields maintaining the equilibrium with the bulk CS fluid are studied on the basis of a recently proposed third order+second order perturbation density functional approximation (DFA). The accuracy of DFA predictions is tested against the results of a grand canonical ensemble Monte Carlo simulation. Reasonable agreement between the results of both methods proves that the DFA theory applied in this work is a convenient theoretical tool for the investigation of the CS fluid, which is practically applicable for modeling numerous real systems.