Light molecules inside the nanocavities of fullerenes and clathrate hydrates: inelastic neutron scattering spectra and the unexpected selection rule from rigorous quantum simulations

The translation-rotation (TR) dynamics and spectroscopy of light molecules, e.g. H 2 , HD, HF, and H 2 O, inside nanoscale cavities such as those of fullerenes and in clathrate hydrates, is dominat...