The crystal structure of Pb7FeIIFe6IIIF34: A new jarlite-type compound

Pb₇Fe^IIFeF₃₄ is monoclinic: a = 16.375(2) Å, b = 11.233(2) Å, c = 7.615(1) Å, β = 102.67(1)º, Z = 2. The crystal structure was solved in the space group C2/m (nº 12), from X-ray single crystal data using 957 independent reflections (705 with F/σ(F) > 4, leading to R = 0.038). It consists in infinite helicoidal Fe^IIFeF₃₄]_n^14n? double-chains of cornersharing octahedra running along the b-axis and separated from each other by lead ions.