Ice VI
Ice VI was discovered by the Nobel prize winner Percy Williams Bridgman in 1912 (Ref. 1), however it seems that its structure was not determined until 1965 by Barclay Kamb (Ref. 2). Ice VI has a density of 1.31 g cm-3. It has a tetragonal cell of dimensions a = 6.27 Å, c = 5.79 Å, space group P42/nmc. Each cell contains ten water molecules (Ref. 3).
References
- Percy Williams Bridgman "Water in the liquid and five solid forms, under pressure", Proceedings of the American Academy of Arts and Sciences XLVII pp. 441-558 (1912)
- Barclay Kamb "Structure of Ice VI", Science 150 pp. 205-209 (1965)
- W. F. Kuhs, J. L. Finney, C. Vettier and D. V. Bliss "Structure and hydrogen ordering in ices VI, VII, and VIII by neutron powder diffraction", Journal of Chemical Physics 81 pp. 3612-3623 (1984)
- Ove Andersson and G. P. Johari "Spontaneous transformation of water's high-density amorph and a two-stage crystallization to ice VI at 1 GPa: A dielectric study", Journal of Chemical Physics 120 pp. 11662-11671 (2004)
- Carlos Vega, Carl McBride, Eduardo Sanz and Jose L. F. Abascal "Radial distribution functions and densities for the SPC/E, TIP4P and TIP5P models for liquid water and ices Ih, Ic, II, III, IV, V, VI, VII, VIII, IX, XI and XII", Physical Chemistry Chemical Physics 7 pp. 1450 - 1456 (2005)
- G. P. Johari, A. Lavergne, and E. Whalley "Dielectric properties of ice VII and VIII and the phase boundary between ice VI and VII", Journal of Chemical Physics 61 pp. 4292-4300 (1974)