The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
S. Sokolowski - One of the best experts on this subject based on the ideXlab platform.
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Direct Correlation Function for complex square barrier square well potentials in the first order mean spherical approximation
Journal of Chemical Physics, 2011Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:The Direct Correlation Function of the complex discrete potential model fluids is obtained as a linear combination of the first-order mean spherical approximation (FMSA) solution for the simple square well model that has been reported recently [Hlushak et al., J. Chem. Phys. 130, 234511 (2009)]. The theory is employed to evaluate the structure and thermodynamics of complex fluids based on the square well-barrier and square well-barrier-well discrete potential models. Obtained results are compared with theoretical predictions of the hybrid mean spherical approximation, already reported in the literature [Guillen-Escamilla et al., J. Phys.: Condens. Matter 19, 086224 (2007)], and with computer simulation data of this study. The compressibility route to thermodynamics is then used to check whether the FMSA theory is able to predict multiple fluid–fluid transitions for the square barrier-well model fluids.
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Direct Correlation Function of the square well fluid with attractive well width up to two particle diameters
Journal of Chemical Physics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:Analytical expression for Direct Correlation Function of the square-well fluid with an attractive well width up to two particle diameters (2<λ≤3) is reported. This result is obtained within the first-order mean-spherical approximation (FMSA) and represents the nontrivial extension of the recent study due to Tang [J. Chem. Phys. 127, 164504 (2007)], where the width of square-well attraction was limited by one particle diameter (1<λ≤2). Prediction of the FMSA theory is validated by Direct comparison against Monte Carlo simulation data. Additionally, an impact of the increase in the range of attraction on the parameters of the critical point of the square-well fluid is discussed using the compressibility route to thermodynamics.
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Direct Correlation Function of square well fluid with wide well: First order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2
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Direct Correlation Function of square well fluid with wide well first order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2
S. P. Hlushak - One of the best experts on this subject based on the ideXlab platform.
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Direct Correlation Function for complex square barrier square well potentials in the first order mean spherical approximation
Journal of Chemical Physics, 2011Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:The Direct Correlation Function of the complex discrete potential model fluids is obtained as a linear combination of the first-order mean spherical approximation (FMSA) solution for the simple square well model that has been reported recently [Hlushak et al., J. Chem. Phys. 130, 234511 (2009)]. The theory is employed to evaluate the structure and thermodynamics of complex fluids based on the square well-barrier and square well-barrier-well discrete potential models. Obtained results are compared with theoretical predictions of the hybrid mean spherical approximation, already reported in the literature [Guillen-Escamilla et al., J. Phys.: Condens. Matter 19, 086224 (2007)], and with computer simulation data of this study. The compressibility route to thermodynamics is then used to check whether the FMSA theory is able to predict multiple fluid–fluid transitions for the square barrier-well model fluids.
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Direct Correlation Function of the square-well fluid with attractive well width up to two particle diameters.
The Journal of chemical physics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, Stefan SokołowskiAbstract:Analytical expression for Direct Correlation Function of the square-well fluid with an attractive well width up to two particle diameters (2
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Direct Correlation Function of the square well fluid with attractive well width up to two particle diameters
Journal of Chemical Physics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:Analytical expression for Direct Correlation Function of the square-well fluid with an attractive well width up to two particle diameters (2<λ≤3) is reported. This result is obtained within the first-order mean-spherical approximation (FMSA) and represents the nontrivial extension of the recent study due to Tang [J. Chem. Phys. 127, 164504 (2007)], where the width of square-well attraction was limited by one particle diameter (1<λ≤2). Prediction of the FMSA theory is validated by Direct comparison against Monte Carlo simulation data. Additionally, an impact of the increase in the range of attraction on the parameters of the critical point of the square-well fluid is discussed using the compressibility route to thermodynamics.
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Direct Correlation Function of square well fluid with wide well: First order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2
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Direct Correlation Function of square well fluid with wide well first order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2
Shiqi Zhou - One of the best experts on this subject based on the ideXlab platform.
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polymer density Functional theory approach based on scaling second order Direct Correlation Function
Journal of Colloid and Interface Science, 2006Co-Authors: Shiqi ZhouAbstract:A second-order Direct Correlation Function (DCF) from solving the polymer-RISM integral equation is scaled up or down by an equation of state for bulk polymer, the resultant scaling second-order DCF is in better agreement with corresponding simulation results than the un-scaling second-order DCF. When the scaling second-order DCF is imported into a recently proposed LTDFA-based polymer DFT approach, an originally associated adjustable but mathematically meaningless parameter now becomes mathematically meaningful, i.e., the numerical value lies now between 0 and 1. When the adjustable parameter-free version of the LTDFA is used instead of the LTDFA, i.e., the adjustable parameter is fixed at 0.5, the resultant parameter-free version of the scaling LTDFA-based polymer DFT is also in good agreement with the corresponding simulation data for density profiles. The parameter-free version of the scaling LTDFA-based polymer DFT is employed to investigate the density profiles of a freely jointed tangent hard sphere chain near a variable sized central hard sphere, again the predictions reproduce accurately the simulational results. Importance of the present adjustable parameter-free version lies in its combination with a recently proposed universal theoretical way, in the resultant formalism, the contact theorem is still met by the adjustable parameter associated with the theoretical way.
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Density Functional Theory Based on the Universality Principle and Third-Order Expansion Approximation for Adhesive Hard-Sphere Fluid near Surfaces
Journal of Physical Chemistry B, 2001Co-Authors: Shiqi ZhouAbstract:The high-order perturbative density Functional theory (Phys. Rev. E 2000, 61, 2704) was reformulated to be adapted for a nonuniform Lennard-Jones fluid with an attractive tail included in the interaction potential as a whole. The second-order Direct Correlation Function of a uniform adhesive hard-sphere fluid was divided into a hard-sphere-like part and an attractive-tail part, and then the density Functional formalism based on the universality principle and bridge Function concept was employed to treat the nonuniform first-order Direct Correlation Function for the hard-sphere-like part. The reformulated high-order perturbative density Functional theory was employed to treat the attractive-tail part for the nonuniform case. The two parts were added together to construct the nonuniform first-order Direct Correlation Function of the adhesive hard-sphere fluid. Then, the ensued result was substituted into the density profile equation in the density Functional theory to predict the nonuniform density distribu...
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A density Functional theory based on the universality of the free energy density Functional
The Journal of Chemical Physics, 2000Co-Authors: Shiqi Zhou, Eli RuckensteinAbstract:A methodology for classical density Functional theory is proposed which expresses the first order Direct Correlation Function for nonuniform systems in terms of the second order Direct Correlation Function and the bridge Function of the corresponding uniform systems. Its applicability to nonuniform systems is verified by applying the approach to three concrete cases, namely, to a hard sphere fluid in a spherical cavity, a hard sphere fluid near a hard wall, and a hard sphere fluid near a 9–3 soft wall. The present density Functional theory (DFT) provides a recipe by which the integral equation theories for uniform systems can be transformed into the corresponding DFTs for nonuniform systems.
Yiping Tang - One of the best experts on this subject based on the ideXlab platform.
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Improved Direct Correlation Function for Density Functional Theory Analysis of Pore Size Distributions
The Journal of Physical Chemistry C, 2009Co-Authors: Ming Zeng, Yiping Tang, Chongli ZhongAbstract:An improved Direct Correlation Function is proposed and applied to construct an accurate free energy Functional. The theoretical method is extended to analyze the pore size distributions (PSDs) of both slit- and cylindrical-shaped carbonaceous materials. With the same parameters for the fluid and material as in the simulation, the model is much more advantageous than the known density Functional methods for calculating the adsorption isotherms in individual pores. The overall PSDs for two model carbons are evaluated for CH4, CF4, and SF6 absorbates, and good results are obtained. The results are reliable because the two model carbons have structures that are exactly known. Encouraged by the success with slit pores, we further extend the model to the internal cylindrical space of a single-walled carbon nanohorn. The PSDs of the carbon nanohorn are evaluated, and satisfactory results are again obtained.
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Direct Correlation Function for the square-well potential.
The Journal of chemical physics, 2007Co-Authors: Yiping TangAbstract:An analytical expression of Direct Correlation Function (DCF) for the square-well potential is developed. The development is based on the first-order mean spherical approximation and its extension to the Functionality of the existing radial distribution Function. The developed DCF is a combination of a special polynomial Function introduced in this work. The combination is piecewise in four regions [0,λ−1], [λ−1,2−λ], [2−λ,1], and [1,λ] for λ 1.5. In addition, the DCF is continuous to second-order inside hard core and discontinuous at r=1 and r=λ outside it. The behavior of DCF is analyzed by some detail calculations.
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modeling inhomogeneous van der waals fluids using an analytical Direct Correlation Function
Physical Review E, 2004Co-Authors: Yiping TangAbstract:Rosenfeld's perturbative method [J. Chem. Phys. 98, 8126 (1993)]] for constructing the Helmholtz energy Functional of classical systems is applied to studying inhomogeneous Lennard-Jones fluids, in which the key input-the bulk Direct Correlation Function-is obtained from the first-order mean-spherical approximation (FMSA) [J. Chem. Phys. 118, 4140 (2003)]]. Preserving its high fidelity at the bulk limit, the FMSA shows stable and satisfactory performance for a variety of inhomogeneous Lennard-Jones fluids including those near hard walls, inside slit pores, and around colloidal particles. In addition, the inhomogeneous FMSA reproduces reliably the radial distribution Function at its bulk limit. The FMSA is found, in particular, much better than the mean-field theory for fluids near hard surfaces. Unlike alternative non-mean-field approaches, the FMSA is computationally as efficient as the mean-field theory, free of any numerical determination of structure information, weight Functions, or empirical parameters.
A. Trokhymchuk - One of the best experts on this subject based on the ideXlab platform.
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Direct Correlation Function for complex square barrier square well potentials in the first order mean spherical approximation
Journal of Chemical Physics, 2011Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:The Direct Correlation Function of the complex discrete potential model fluids is obtained as a linear combination of the first-order mean spherical approximation (FMSA) solution for the simple square well model that has been reported recently [Hlushak et al., J. Chem. Phys. 130, 234511 (2009)]. The theory is employed to evaluate the structure and thermodynamics of complex fluids based on the square well-barrier and square well-barrier-well discrete potential models. Obtained results are compared with theoretical predictions of the hybrid mean spherical approximation, already reported in the literature [Guillen-Escamilla et al., J. Phys.: Condens. Matter 19, 086224 (2007)], and with computer simulation data of this study. The compressibility route to thermodynamics is then used to check whether the FMSA theory is able to predict multiple fluid–fluid transitions for the square barrier-well model fluids.
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Direct Correlation Function of the square-well fluid with attractive well width up to two particle diameters.
The Journal of chemical physics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, Stefan SokołowskiAbstract:Analytical expression for Direct Correlation Function of the square-well fluid with an attractive well width up to two particle diameters (2
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Direct Correlation Function of the square well fluid with attractive well width up to two particle diameters
Journal of Chemical Physics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:Analytical expression for Direct Correlation Function of the square-well fluid with an attractive well width up to two particle diameters (2<λ≤3) is reported. This result is obtained within the first-order mean-spherical approximation (FMSA) and represents the nontrivial extension of the recent study due to Tang [J. Chem. Phys. 127, 164504 (2007)], where the width of square-well attraction was limited by one particle diameter (1<λ≤2). Prediction of the FMSA theory is validated by Direct comparison against Monte Carlo simulation data. Additionally, an impact of the increase in the range of attraction on the parameters of the critical point of the square-well fluid is discussed using the compressibility route to thermodynamics.
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Direct Correlation Function of square well fluid with wide well: First order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2
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Direct Correlation Function of square well fluid with wide well first order mean spherical approximation
arXiv: Statistical Mechanics, 2009Co-Authors: S. P. Hlushak, A. Trokhymchuk, S. SokolowskiAbstract:An analytical expression for square-well fluid Direct Correlation Function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2