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David A Kofke - One of the best experts on this subject based on the ideXlab platform.

  • exact solution for the Singlet Density distributions and second order correlations of normal mode coordinates for hard rods in one dimension
    Journal of Chemical Physics, 1999
    Co-Authors: Daniel C Barnes, David A Kofke
    Abstract:

    We examine the distribution of normal-mode coordinates (defined via the eigenvectors of a chain of harmonic oscillators) for a system of purely repulsive hard rods in one dimension. We obtain an exact solution for the Singlet Density distribution, and separately for the covariances of the normal-mode coordinates. The hard-rod behavior is examined in terms of its deviation from the corresponding distributions for the system of harmonic oscillators. All off-diagonal covariances are zero in the hard-rod system, and the (on-diagonal) variances vary with the normal-mode wave number exactly as in the harmonic system. The detailed Singlet normal-mode Density distributions are very smooth but nonanalytic, and they differ from the (Gaussian) distributions of the corresponding harmonic system. However, all of the normal-mode coordinate distributions differ in roughly the same way when properly scaled by the distribution variance, and the differences vanish as 1/N in the thermodynamic limit of an infinite number of particles N.

Daniel C Barnes - One of the best experts on this subject based on the ideXlab platform.

  • exact solution for the Singlet Density distributions and second order correlations of normal mode coordinates for hard rods in one dimension
    Journal of Chemical Physics, 1999
    Co-Authors: Daniel C Barnes, David A Kofke
    Abstract:

    We examine the distribution of normal-mode coordinates (defined via the eigenvectors of a chain of harmonic oscillators) for a system of purely repulsive hard rods in one dimension. We obtain an exact solution for the Singlet Density distribution, and separately for the covariances of the normal-mode coordinates. The hard-rod behavior is examined in terms of its deviation from the corresponding distributions for the system of harmonic oscillators. All off-diagonal covariances are zero in the hard-rod system, and the (on-diagonal) variances vary with the normal-mode wave number exactly as in the harmonic system. The detailed Singlet normal-mode Density distributions are very smooth but nonanalytic, and they differ from the (Gaussian) distributions of the corresponding harmonic system. However, all of the normal-mode coordinate distributions differ in roughly the same way when properly scaled by the distribution variance, and the differences vanish as 1/N in the thermodynamic limit of an infinite number of particles N.

J G Muga - One of the best experts on this subject based on the ideXlab platform.

  • moderately dense gas quantum kinetic theory transport coefficient expressions
    Journal of Chemical Physics, 1996
    Co-Authors: R F Snider, Guowei Wei, J G Muga
    Abstract:

    Expressions for the transport coefficients of a moderately dense gas are obtained, based on a recently derived Density corrected quantum Boltzmann equation. Linearization of the equations determining the pair correlation and the ‘‘free’’ Singlet Density operators about local equilibrium is discussed first. The rate of change of the pair correlations is treated as dynamic effects for pairs of particles relaxing to local equilibrium via a relaxation time model arising from interactions with ‘‘third particles.’’ In contrast, the Singlet Density operator satisfies a Boltzmann equation with binary collisions. Spatially inhomogeneous corrections to the collision superoperator are included. Contributions to the transport coefficients arise from the perturbation from local equilibrium through fluxes associated with kinetic, collisional and, for the thermal conductivity, potential energy mechanisms. A comparison is made between the classical limit of the transport coefficient expressions obtained here and the clas...

R F Snider - One of the best experts on this subject based on the ideXlab platform.

  • moderately dense gas quantum kinetic theory transport coefficient expressions
    Journal of Chemical Physics, 1996
    Co-Authors: R F Snider, Guowei Wei, J G Muga
    Abstract:

    Expressions for the transport coefficients of a moderately dense gas are obtained, based on a recently derived Density corrected quantum Boltzmann equation. Linearization of the equations determining the pair correlation and the ‘‘free’’ Singlet Density operators about local equilibrium is discussed first. The rate of change of the pair correlations is treated as dynamic effects for pairs of particles relaxing to local equilibrium via a relaxation time model arising from interactions with ‘‘third particles.’’ In contrast, the Singlet Density operator satisfies a Boltzmann equation with binary collisions. Spatially inhomogeneous corrections to the collision superoperator are included. Contributions to the transport coefficients arise from the perturbation from local equilibrium through fluxes associated with kinetic, collisional and, for the thermal conductivity, potential energy mechanisms. A comparison is made between the classical limit of the transport coefficient expressions obtained here and the clas...

Guowei Wei - One of the best experts on this subject based on the ideXlab platform.

  • moderately dense gas quantum kinetic theory transport coefficient expressions
    Journal of Chemical Physics, 1996
    Co-Authors: R F Snider, Guowei Wei, J G Muga
    Abstract:

    Expressions for the transport coefficients of a moderately dense gas are obtained, based on a recently derived Density corrected quantum Boltzmann equation. Linearization of the equations determining the pair correlation and the ‘‘free’’ Singlet Density operators about local equilibrium is discussed first. The rate of change of the pair correlations is treated as dynamic effects for pairs of particles relaxing to local equilibrium via a relaxation time model arising from interactions with ‘‘third particles.’’ In contrast, the Singlet Density operator satisfies a Boltzmann equation with binary collisions. Spatially inhomogeneous corrections to the collision superoperator are included. Contributions to the transport coefficients arise from the perturbation from local equilibrium through fluxes associated with kinetic, collisional and, for the thermal conductivity, potential energy mechanisms. A comparison is made between the classical limit of the transport coefficient expressions obtained here and the clas...