K Mg (Nb (O2)4) (H2 O)7

H₁₄KMgNbO₁₅

Mathern, G.Weiss, R.

Acta Crystallographica, Section B: Structural Crystallography and Crystal Chemistry (1971) 27, 8 1598-1609

a=11.95Å   b=12.19Å   c=14.08Å

α=90°   β=141.2°   γ=90°