Abstract
The crystal structures of dirubidium potassium dysprosium bis-(vanadate), Rb(2)KDy(VO(4))(2), and caesium potassium gadolinium bis-(vanadate), Cs(1.52)K(1.48)Gd(VO(4))(2), were solved from single-crystal X-ray diffraction data. Both compounds, synthesized by the reactive flux method, crystallize in the space group P m1 with the glaserite structure type. VO(4) tetra-hedra are linked to DyO(6) or GdO(6) octa-hedra by common vertices to form sheets stacking along the c axis. The large twelve-coordinate Cs(+) or Rb(+) cations are sandwiched between these layers in tunnels along the a and b axes, while the K(+) cations, surrounded by ten oxygen atoms, are localized in cavities.