(H3O)(2)[V-4(HPO4)(PO4)(3)O6F](2)[NC7H14](6) (labeled ULM-17) has been hydrothermally synthesized (150 degrees, 24 h, autogeneous pressure). It is monoclinic (space group P2(1/c) (No. 14)) with a = 21.4747(6) Angstrom, b = 17.7223(5) Angstrom, c = 20.1616(6) Angstrom, beta = 94.329(1)degrees, and Z = 4. The structure consists in the hexagonal close packing of discrete hydronium cations, protonated quinuclidine and molecular anions [V-4(HPO4)(PO4)(3)O6F](4-) (1) The structure presents two kinds of octameric anions built up from the tetrahedral arrangement of (VO5F)-O-V octahedra sharing edges and vertices, capped by phosphorus tetrahedra. The stability of the solid is ensured via strong hydrogen bonds between the oxygens of the polyanions and the hydrogens of both hydronium and quinuclidinium cations. The particuliar location of fluorine at the center of the molecular anion 4-fold coordinated by V-V was studied by solid state NMR.