A Chiral Gas-Hydrate Structure Common to the Carbon Dioxide-Water and Hydrogen-Water Systems.

We present full in situ structural solutions of carbon dioxide hydrate-II and hydrogen hydrate C at elevated pressures using neutron and X-ray diffraction. We find both hydrates adopt a common water network structure. The structure exhibits several features not previously found in hydrates; most notably it is chiral and has large open spiral channels along which the guest molecules are free to move.