Crystal structures and X-ray powder diffraction data for AAlGe₂O₆ synthetic leucite analogs (A = K, Rb, Cs)

Leucites are tetrahedrally coordinated silicate framework structures with some of the silicon framework cations that are partially replaced by divalent or trivalent cations. These structures have general formulae A(2)BSi(5)O(12) and ACSi(2)O(6), where A is a monovalent alkali metal cation, B is a divalent cation, and C is a trivalent cation. There are also leucite analogs with analogous tetrahedrally coordinated germanate framework structures. These have general formulae A(2)BGe(5)O(12) and ACGe(2)O(6). In this paper, the Rietveld refinements of three synthetic Ge-leucite analogs with stoichiometries of AAlGe(2)O(6) (A = K, Rb, Cs) are discussed. KAlGe2O6 is I4(1)/a tetragonal and is isostructural with KAlSi2O6. RbAlGe2O6 and CsAlGe2O6 are I((4) over bar)3d cubic and are isostructural with KBSi2O6. (c) The Author(s), 2024. Published by Cambridge University Press on behalf of International Centre for Diffraction Data.