Abstract
Neutron diffraction measurements on ice VII and ice VIII at pressures up to 20 GPa provide direct evidence of multisite disorder of both oxygen and deuterium atoms in ice VII, and give the magnitudes of the site separations. An O-D distance and D-Ô-D angle closest to those found in ice VIII are obtained with oxygen sites displaced along directions. Such displacements imply an H-bond geometry significantly different from that found in ice VIII, and this may have implications for the centering transition to ice X.
- Received 5 May 1997
DOI:https://doi.org/10.1103/PhysRevLett.81.2719
©1998 American Physical Society