The discovery of metastable ice XVII, which has a porous structure, suitable to be filled with hydrogen and other gases, has prompted our group to measure on TOSCA neutron scattering spectra on this ice containing molecular hydrogen. Analogously to the results obtained for sII and sH hydrogen-filled clathrate hydrates, these measurements have disclosed the quantum dynamics of the guest H2 molecules inside the host. This proposal aims to study the dynamics of monatomic and non-hydrogenous molecular gases, filling the channels of ice XVII. This experiment will also explore the detectability limits of the new TOSCA-III configuration for non-hydrogenous samples.