Synthesis and Crystal Structure of a New Lithium Nickel Fluorophosphate Li2[NiF(PO4)] with an Ordered Mixed Anionic Framework

A new lithium nickel fluorophosphate Li2[NiF(PO4)] has been synthesized. It crystallizes in the orthorhombic system with unitcell parametersa=10.473(3) ?,b=6.2887(8) ?,c=10.846(1) ?, and space groupPnma(no. 62),Z=8. Its structure has been determined from single-crystal X-ray diffraction data and refined to a conventionalR=0.030 (Romega=0.033) for 647 reflections withI>3sigma (I). The structure is built of infinite chains of a rutile type of NiO4F2octahedra running along thebdirection further joined together by isolated PO4tetrahedra by sharing corners. This three-dimensional framework delimits channels parallel to thebdirection where the Li+ions lie. This compound is characterized by a rigorous O–F ordering.