O4SiU
Fuchs, L. H.Gebert, E.
American Mineralogist (1958) 43, 243-248
a=6.995Å b=6.995Å c=6.263Å
α=90° β=90° γ=90°
O4SiTh
a=7.142Å b=7.142Å c=6.327Å