K₂V₂O₂(AsO₄)₂.

The vanadium oxide arsenate with formula K₂V₂O₂(AsO₄)₂, dipotassium divanadium(IV) dioxide diarsenate, has been synthesized by solid-state reaction in an evacuated silica ampoule. Its structure is isotypic with K₂V₂O₂(PO₄)₂. The framework is built up from corner-sharing VO₆ octa-hedra and AsO₄ tetra-hedra, creating an infinite [VAsO₈](∞) chain running along the a- and c-axis directions.

K(1.65)V(1.78)W(0.22)O(2)(AsO(4))(2).

The title potassium vanadium tungsten bis-(arsenate oxide) was synthesized by a solid-state reaction at 973 K. The crystal structure is isotypic with KVOPO(4) and contains a [MVAs(2)O(10)](∞) framework built up from single MO(6) (M = V+W) octa-hedra sharing corners with single VO(6) octa-hedra and AsO(4) tetra-hedra. This structure shows the existence of infinite [VAsO(8)](∞) and [MAsO(8)](∞) chains running along the a and c directions, respectively.