This proposal seeks to measure the poly-CINS (polycrystalline coherent inelastic neutron scattering) spectrum from magnesium deuteride (MgD2); a powder sample on the MARI spectrometer. This is a continuation of an existing data gathered on the MARI spectrometer that shows good data over the range of vibrational modes in powder MgD2. Now temperature dependent information is sought for the Q dependence of both low frequency Mg modes and the interactions between Mg and H at a range of temperatures (5K through to 450K), with the primary aim being the generation of a temperature - dependent semi-empirical magnesium-hydrogen potential for the prediction of the dynamics of this system and other, more complex, magnesium-hydrogen systems.