Molecular dynamics study of the incoherent and coherent contributions to the total dynamic structure factor of molten NaI

Molecular dynamics simulations of molten NaI have been made using two different models, one having fairly similar ionic sizes, and the other having an anionic radius larger than the cationic one. The incoherent and coherent contributions to the total dynamic structure factor have been analysed in terms of the self, mass, and charge density fluctuations. The corresponding intermediate scattering functions and dynamic structure factors have been calculated for a wide range of wave numbers, from 0.175 Å− 1, near the hydrodynamic limit, to 6.1 Å− 1, approaching the free particle limit.