Al2F2O4Si
Northrup, P. A.Leinenweber, K.Parise, J. B.
American Mineralogist (1994) 79, 401-404
a=4.652Å b=8.801Å c=8.404Å
α=90° β=90° γ=90°
Al2H2O6Si
a=4.7203Å b=8.9207Å c=8.4189Å