Finding Order in Disorder - The Highly Disordered Lithium Oxonitridophosphate Double Salt Li8+ x P3O10- x N1+ x (x = 1.4(5)).

The crystalline lithium oxonitridophosphate Li8+xP3O10-xN1+x was synthesized in an ampoule synthesis from P3N5 and Li2O. The compound crystallizes in the triclinic space group P[[EQUATION]] with a = 5.125(2), b = 9.888(5), c = 10.217(5) Å, α = 70.30(2), β = 76.65(2), γ = 77.89(2)°. Li8+xP3O10-xN1+x is a double salt, the structure of which contains distinctive complex anion species, namely non-condensed P(O,N)4 tetrahedra, and P(O,N)7 double tetrahedra connected by one N atom. Additionally, there is mixed occupation of O/N positions, which enables further anionic species by variation of O/N occupancies. To characterize these motifs in detail, complementary analytical methods were applied. The double tetrahedron exhibits significant disorder in single-crystal X-ray diffraction. Furthermore, the title compound is a Li+ ion conductor with a total ionic conductivity of 1.2 × 10-7 S cm-1 at 25 °C, and a corresponding total activation energy of 0.47(2) eV.