AM_Pb6[Ge6O18]2H20 Formula: Pb3 Ge3 O10 H2 Name: Pb6[Ge6O18].2H20 Unit cell: 15.6476 15.6476 7.3119 90.0 90.0 120.0 , V=1550.44 Space group: R11-3 (1)

Otto H H , Brandt H J , European Journal of Mineralogy , 8 (1996) p.301-310, Crystal structure of Pb6[Ge6O18]2H2O, a lead cyclo-germanate, similar to the mineral dioptase