Abstract: | A new microporous zirconogermanate, diammonium zirconium trigermanate, (NH4)2ZrGe3O9 (FDZG‐2), analogous to wadeite (K2ZrSi3O9), was hydrothermally synthesized using ZrO(NO3)2·2H2O as the source of zirconium and 1,4‐diaminobutane as a structure‐directing agent. Single‐crystal X‐ray diffraction analysis reveals that the framework structure is built up of cyclic trigermanate units crosslinked by ZrO6 octahedra. The Zr atom lies at a site with symmetry and the unique N atom of the ammonium ion lies at a site with threefold symmetry. Large cages are observed, with two NH4+ cations in each. The structure contains intersecting six‐ and three‐membered ring (6MR and 3MR) channels, but only the 6MR channels can accommodate the NH4+ ions. |