The objective of this proposal is to characterise the network dynamics for a range of GexSe1-x glasses (0 < x < 1) by using inelastic neutron spectroscopy to measure the vibrational density of states (VDOS). GexSe1-x is chosen because it is a prototypical covalently bonded network glass forming system in which a variety of structural motifs occur such that the liquid can self-organise on glass formation to give the so-called intermediate phase. Glasses within this phase, which covers the range 0.20 < x < 0.26, are stress free and stable in that their properties do not appear to age. The results will be used in conjunction with neutron diffraction and first-principles molecular dynamics simulations to build accurate atomistic models of the network glasses and to help elucidate the origin of the intermediate phase.