The object of this proposal is to measure the partial dynamical structure factors and the partial vibrational density of states (VDOS) for the archetypal network forming glass GeSe2 by using the method of isotope substitution in neutron scattering. The work builds on an initial experiment using MARI where the partial VDOS for this material were extracted within the incoherent approximation. We now wish to take advantage of the attributes of MERLIN to separate the contributions to the scattering from all three partial dynamical structure factors S_GeGe(Q, E), S_SeSe(Q, E) and S_GeSe(Q, E) and hence obtain the partial VDOS for Ge and Se by integrating over the separated Ge-Ge and Se-Se partial structure factors, respectively. Recent ab initio molecular dynamics simulations on a variety of network glasses show that the partial VDOS thus obtained will be exact.