A new open-framework zinc arsenate [C<SUB>4</SUB>N<SUB>3</SUB>H<SUB>16</SUB>]<SUB>2</SUB>[Zn<SUB>5</SUB>(AsO<SUB>4</SUB>)<SUB>4</SUB>(HAsO<SUB>4</SUB>)<SUB>2</SUB>]

A three-dimensional zinc arsenate with an interrupted zeolitic framework (-IIO), [C4N3H16]2[Zn5(AsO4) 4(HAsO4)2], I has been synthesized solvothermally. The structure is built up from ZnO4, AsO4 and HAsO4 tetrahedral units connected alternatively through their vertices forming the 3-D structure possessing one-dimensional channels bound by 10 T-atoms (T = Zn, As). The framework density of the structure is 10.4 T-atoms which indicates considerable openness in its structure