Statistical mechanics of dense ionized matter. IV. Density and charge fluctuations in a simple molten salt
- 1 June 1975
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review A
- Vol. 11 (6), 2111-2123
- https://doi.org/10.1103/physreva.11.2111
Abstract
The results of a molecular-dynamics study of a simple model of a molten salt are reported. The interionic pair potential which is used consists of the Coulombic term an an inverse-power repulsion which is assumed to be the same for all ions. The structure of the liquid is found to be dominated by charge-ordering effects and the calculated equilibrium properties are in good agreement with the predictions of the hypernetted-chain approximation. The relation between the self-diffusion coefficient and the electrical conductivity is discussed, and the observed deviations from the Nernst-Einstein relation in real molten salts are shown to have a natural explanation in terms of short-lived cross correlations. Data on the spectra of charge and particle density fluctuations are presented. At small wave numbers there is a propagating optic-type mode which shows a strong negative dispersion, but no Brillouin peak is seen even at the lowest wave number which is accessible. The data are analyzed in terms of a single-relaxation-time model incorporating the low-order spectral moments, for which we give explicit formulas. The fit achieved is fair, but the low-frequency behavior of the charge fluctuations at small wave numbers is incorrectly reproduced, and there is evidence for the necessity of introducing a second relaxation time. Comparison is made with results previously obtained for the classical one-component plasma.Keywords
This publication has 23 references indexed in Scilit:
- Statistical mechanics of dense ionized matter. III. Dynamical properties of the classical one-component plasmaPhysical Review A, 1975
- Thermodynamic properties and self-diffusion of molten sodium chloride. A molecular dynamics studyJournal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 1975
- Self-diffusion and electrical conductance in a simple molten saltJournal of Physics C: Solid State Physics, 1974
- Propagation of Density Fluctuations in Liquid Rubidium: A Molecular-Dynamics StudyPhysical Review Letters, 1974
- Density fluctuations in classical monatomic liquidsJournal of Physics C: Solid State Physics, 1971
- An Empirical Corresponding States Correlation of Densities and Transport Properties of 1-1 Alkali Metal Molten SaltsIndustrial & Engineering Chemistry Fundamentals, 1971
- Effects of a Volume-Dependent Potential on Equilibrium Properties of Liquid SodiumPhysical Review A, 1971
- Fluctuation Analysis in Simple FluidsPhysical Review A, 1970
- Liquid dynamics and inelastic scattering of neutronsPhysica, 1959
- The compressibilities, free volumes and equation of state for molten electrolytes: some alkali halides and nitratesProceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1957