Ringwoodite

H_0.3Mg_1.89O₄Si_0.98

Kudoh, Y.Kuribayashi, T.Mizobata, H.Ohtami, E.

Physics and Chemistry of Minerals (2000) 27, 474-479

a=8.0693Å   b=8.0693Å   c=8.0693Å

α=90°   β=90°   γ=90°