Self-consistent calculation of excitation spectra in simple molten salts

The dynamical properties of simple molten salts are studied through the mass and charge density correlation functions as well as through the autocorrelation functions for the velocity and for the total electric current. Employing the Mori memory function approach and following an earlier treatment of Hansen and Sjögren concerning the mass and charge fluctuations, the problem reduces to calculating the memory functions for the velocity and total electric current autocorrelation functions. Here, these memory functions are split into a binary collision part and a collective recollision part and the latter is expressed in terms of certain mode–mode coupling integrals. The resulting nonlinear equations are solved self-consistently by numerical means. Comparison is made with molecular dynamics results of Hansen and McDonald. It is found that the present theory is in semiquantitative agreement with the computer data. The reasons for some of the discrepancies are also discussed and explained.