Major advantages of a synchrotron is the energy tunability and very high brightness. These unique properties permit different types of spectroscopy which probe different physical and electronic properties to be performed. In this presentation, various experiments, from infrared (∼0.01 eV) to Compton scattering (125 keV), on ice and clathrate hydrates will be discussed. Using low‐temperature infrared spectroscopy, we have studied the mechanism for the novel iso‐structural phase transition of high pressure ice‐VIII. High resolution powder diffraction using high energy radiation was used to provide very accurate atom radial distribution functions for the characterization of the structural changes associated with the HDA to LDA ice transformation. Very high energy x‐ray was used to study the interactions between simple rare gas atoms and methane with the ice framework in clathrate hydrates. The “resonant scattering” of the guests with the ice vibrations was identified using x‐ray scattering and the specific role of the guest, in particular Kr in Kr hydrate was studied with the nuclear inelastic scattering technique. © 2004 American Institute of Physics