Dilithium disodium nickel(II) cyclo­hexa­phosphate dodeca­hydrate, Li(2)Na(2)NiP(6)O(18)·12H(2)O

The crystal structure of Li(2)Na(2)NiP(6)O(18)·12H(2)O is characterized by the presence of six-membered P(6)O(18) (6−) phosphate ring anions (inter­nal symmetry -1) having a chair conformation and three different cations, viz. Li(+), Na(+) and Ni(2+), to counterbalance the anionic charge. All atoms are in general positions except for nickel, which lies on a special position with site symmetry 2. Lithium has a tetra­hedral environment (LiO(4)), and sodium and nickel have octa­hedral environments [NaO(6) and Ni(H(2)O)(6), respectively]. The P(6)O(18) rings are linked via corner sharing by NaO(6) octa­hedra and LiO(4) tetra­hedra to form a three-dimensional framework presenting tunnels running along [010] in which the six-coordinated Ni(2+) cations are located. The structure is stabilized by a network of O—H⋯O hydrogen bonds.