CRYSTAL-STRUCTURE OF THE DIPHOSPHATE SRCUP2O7

The structure of SrCuP2O7 is isostructural with that of CaCuP2O7 and related to that of α-Ca2P2O7. SrCuP2O7 crystallizes in the monoclinic space group P 21/n with lattice parameters a = 12.455(2) Å, b = 8.129(1) Å, c = 5.369(1) Å, and β = 90.59(1)°. A total of 1386 independent reflections (I ≥ 3 σ(I)) have been used to refine the structure to R = 0.046 (Rw = 0.044). The mixed framework of the structure is built up with CuO5 and P2O7 units which define infinite tunnels along [001] direction where strontium atoms are located. Copper ions occupy isolated square pyramidal sites. © 1993 Academic Press, Inc.