‘‘Prepeaks’’ and ‘‘first sharp diffraction peaks’’ in computer simulations of strong and fragile ionic liquids

Computer simulations with polarizable anions are shown to reproduce the distinctive prepeak observed in diffraction studies of molton ${\mathrm{ZnCl}}_2$ and its mixtures with alkali chlorides. Two distinct origins for the peak in the microscopic structure of the melts are identified. The influence of alkali cation size on the observed behavior is explained. The relationship between the observation of prepeaks and the existence of network structures in strong ionic liquids is discussed.