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Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Iowa State University

2001

Selected Works

Statistical, Nonlinear, and Soft Matter Physics

Articles 1 - 2 of 2

Full-Text Articles in Physics

Classical Density Functional Theory Of Freezing In Simple Fluids: Numerically Induced False Solutions, M. Valera, F. J. Pinski, Duane D. Johnson Nov 2001

Classical Density Functional Theory Of Freezing In Simple Fluids: Numerically Induced False Solutions, M. Valera, F. J. Pinski, Duane D. Johnson

Duane D. Johnson

Density functional theory (DFT) has provided many insights into the freezing of simple fluids. Several analytical and numerical solution have shown that the DFT provides an accurate description of freezing of hard spheres and their mixtures. Compared to other techniques, numerical, grid-based algorithms for solving the DFT equations have more variational freedom and are capable of describing subtle behavior, as that seen in mixtures with multipeaked density profiles. However the grid-based approach is sensitive to the coarseness of the mesh employed. Here we summarize how the granularity of the mesh affects the freezing point within the DFT. For coarse meshes, …


Microscopic Kinetics And Time-Dependent Structure Factors, T. Aspelmeier, Beate Schmittmann, R. K. P. Zia Jul 2001

Microscopic Kinetics And Time-Dependent Structure Factors, T. Aspelmeier, Beate Schmittmann, R. K. P. Zia

Beate Schmittmann

The time evolution of structure factors (SF) in the disordering process of an initially phase-separated lattice depends crucially on the microscopic disordering mechanism, such as Kawasaki dynamics (KD) or vacancy-mediated disordering (VMD). Monte Carlo simulations show unexpected “dips” in the SFs. A phenomenological model is introduced to explain the dips in the odd SFs, and an analytical solution of KD is derived, in excellent agreement with simulations. The presence (absence) of dips in the even SFs for VMD (KD) marks a significant but not yet understood difference of the two dynamics.