Crystal structure of KSbP 2O 8

KSbP ₂O ₈ crystallizes in the rhombohedral system, space group R overline3, with a = 4.7623(4) Å, c = 25.409(4)Å, and Z = 3. The structure was determined from 487 reflexions collected on a NONIUS CAD4 automatic diffractometer with Mo K^-α radiation. The final R index and weighted R_w index are 0.030 and 0.038, respectively. This structure is built up from layers of SbO ₆ octahedra and PO ₄ tetrahedra sharing corners. These (SbP ₂O ^-₈) _n layers are very similar to the (ZrP ₂O ^2-₈) _n layers in the well-known α-ZrP compound.