The proposing team has a well established experience in the use of neutron scattering on samples containing molecular hydrogen. Our recent experimental results on cubic hydrogen clathrate hydrates, obtained on TOSCA, allowed to investigate the quantum dynamics of the guest H2 molecule inside the host cage. These systems may have a relevance from the perspective of new materials suitable for hydrogen storage applications. This proposal aims to study both the host and the lattice dynamics of clathrate hydrates of different structure containing hydrogen (H2, HD and D2), or other gas. From the spectra it will be possible to derive the different dynamics of the molecules inside the cages.