[en] The self-diffusion coefficients D₊ and D_- of the two ionic species in molten AgI, CuCl, CuBr and CuI are evaluated and contrasted with those calculated for molten NaCl. The evaluation adopts a simple model for liquid state dynamics, earlier proposed by Zwanzig to justify the Stokes-Einstein formula for monatomic fluids, and by suitable approximations relates the self-diffusion coefficients to pair potentials and to the pair structure of the melt. The results offer an interpretation for molecular dynamics data showing that, whereas for a ''normal'' system such as NaCl the ratio D₊/D_- in the melt is of the order unity, a sizable difference between D₊ and D_- persists in salts melting from a fast-cation conducting solid. This difference is explicitly related to liquid structure through differences in the structural backscattering of cations by cations and of halogens by halogens. The calculated magnitudes of D₊/D_- are quite satisfactory, while the absolute magnitudes of D₊ and D_- are in good agreement with the data only for those salts (AgI, CuBr and NaCl) in which the masses of the two ionic species are not greatly different. (author). 21 refs, 2 tabs

[en] Expressions for the second and fourth frequency sum rules of the velocity auto-correlation function have been obtained for an isotopic fluid. These expressions and Mori memory function formalism have been used to study the influence of the particle mass and mole fraction on the self diffusion coefficient. Our results confirm the weak mass dependence of the self diffusion. The influence of the mole fraction of the light particles on the self diffusion constant has been found to increase for the larger particle mass. (author). 17 refs, 1 fig., 2 tabs

[en] The anisotropic ionic diffusion coefficients in model electrochemical cells in the molten-salt regime for the electrolyte are evaluated from the ionic density profiles reported in simulation work of Grout and coworkers. A local description of the diffusion processes for counterions and coions in the electrical double layer is obtained from the data. (author). 10 refs, 1 fig., 1 tab

[en] We discuss theoretically (i) the effect of the alkali cation species on the ionic equilibrium between (AlF₆)^3- and (AlF₄)^- complexes in molten alkali fluoroaluminates, and (ii) the possible presence of (AlF₅)² - complexes in molten cryolite, in relation to very recent Raman scattering experiments by Gilbert and Materne. (author). 7 refs, 2 tabs

[en] A simple model is used to calculate the tracer diffusion in a Lennard-Jones tracer-solvent system. The influence of the size ratio between tracer and solvent, and of their mass ratio on the tracer diffusivity is investigated. The adopted model, proposed by Tankeshwar et al., is based on the idea, put forward by Zwanzing, of separating the configurational space of fluid system into a vibrational part and a structural part. The results offer an interpretation of the molecular dynamics data showing a positive deviation from Stokes-Einstein behaviour for small size of the tracer. The deviation is explicitly related to the length parameter of tracer-solvent interaction. The calculated values of the tracer diffusion coefficients for a large range of its size and mass values are quite satisfactory as judged by comparison with simulation results. (author). 12 refs, 4 figs, 1 tab

[en] Scopigno and Ruocco [Phys. Rev. E 70, 013201 (2004)] have raised certain objections to physical interpretation of the parameters of the model proposed by us earlier [Singh and Tankeshwar, Phys. Rev. E 67, 012201 (2003)]. We have found that heat diffusion term enters into processes which are responsible for the quasielastic peak of the dynamical structure factor. An attempt has been made to study the role played by atomic and electronic contributions to thermal conductivity for studying atomic density-density correlation function

[en] The wave vector dependent shear viscosity which appears as memory kernel in the generalized Langevin equation for transverse current-current correlation function has been studied for six thermodynamic states of expanded Rb. The memory kernel has been modelled with all its parameters determined from the microscopic sum rules of transverse current correlation function. The results obtained for the shear viscosity as a function of wave number have been compared with the computer simulation data for the densities ranging from triple point to near the critical point. (author)

[en] We evaluate the ground state properties of a charged Bose gas at T = 0 within the quantum version of the self-consistent field approximation of Singwi, Tosi, Land and Sjoelander (STLS). The dynamical nature of the local field correction is retained to include dynamic correlation effects. The resulting static structure factor S(q) and the local field factor G(q) exhibit properties not described by other mean-field theories. (author). 19 refs, 7 figs

[en] The time evolution of the auto correlation functions of the velocity, transverse stress and energy current density has been calculated using a secant hyperbolic form of the Mori's memory function. Predicted results for the autocorrelation functions and the transport coefficients are compared with molecular dynamics data over a wide range of densities and temperatures. An overall good agreement has been achieved. Results for the dynamical structure factor using the same memory function have been compared with recent neutron scattering data for fluid argon and with MD data for liquid aluminium. These are also found to be very satisfactory for wave numbers up to 2.5 A^-1. (author). 24 refs, 6 figs

[en] Inelastic x-ray scattering data of liquid Li, Na, and Al for dynamical structure factors have been analyzed by proposing a semiempirical model. The model is based on the extension of the hydrodynamic model to the viscoelastic region so that it satisfies the first four nonvanishing sum rules. It has been found that the semiempirical model fits well with the x-ray scattering data for liquid metals investigated here. The physical meaning of the parameters is also discussed