Mineral Structure Data
If you need this information you can look in Smyth and Bish "Crystal Structures and Cation Sites in the Rock-forming Minerals" (1988) Allen and Unwin
Or look in the new AGU Reference volume "Mineral Physics and Crystallography" Thomas J. Ahrens, ed. (1995) American Geophysical Union.
The crystal structure of wadsleyite II.
Mineral Data Base Index