Rede´termination de la structure cristalline de K3NbP2O9

K3NbP2O9, Mr = 416.2, Monoclinic, P21 c, a = 5.214(2), b = 17.695(6), c = 9.751(3)Å, β = 90.48(4)°, V = 899.5Å3, Z = 4, ϱ = 3.07 g/cm3, MoKα, λ = 0.7107Å, μ = 30.4 cm−1, F(000) = 800, R = 0.058, Rw = 0.064 for 675 independent reflections. The structure contains chains of PO4 tetrahedra and NbO6 octahedra sharing corners. They are connected by NbO(2)P bridges to form double chains parallel to the a axis, held together by the K+ ions. The niobium atom is off-center in an “O6” octahedron so that it lies in an “O5” square pyramid. The correct coordination is shown to be 6.