BOSON PEAKS AND SLOW RELAXATION IN A SIMULATION OF A NETWORK-FORMING IONIC MELT

Results are presented for the dynamical properties of a computer simulation model which has previously been shown to reproduce the distinctive structural characteristics of the intermediate-strength liquid glass former ZnCl2. Slow structural relaxation of the density on the length scale of the intermediate-range order is demonstrated, and the implications of this finding for theories of the glass transition in network-forming liquids are discussed qualitatively. A strong boson peak develops in the self-dynamic structure factor (incoherent neutron scattering) as the fluid is supercooled. Its presence is traced to the density of states (spectral density of the velocity autocorrelation function) and also to the intermediate scattering function.