Jumping between water polymorphs

The three site–site partial structure factors of two polymorphs of water have been extrapolated from neutron diffraction experiments exploiting the isotopic H/D substitution performed on pure supercooled water. The low density polymorph has an open hydrogen-bonded structure, while the high density polymorph has non-tetrahedral O–O–O angles and a collapsed second coordination shell, which implies broken hydrogen bonds between the first and second neighboring shells.