Abid Sonia, Al-Deyab Salem S, Rzaigui Mohamed
Acta Crystallogr Sect E Struct Rep Online. 2012 Aug 1;68(Pt 8):i62-i63. doi: 10.1107/S1600536812029960. Epub 2012 Jul 7.
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 (inter-nal 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 tetra-hedral environment (LiO(4)), and sodium and nickel have octa-hedral environments [NaO(6) and Ni(H(2)O)(6), respectively]. The P(6)O(18) rings are linked via corner sharing by NaO(6) octa-hedra and LiO(4) tetra-hedra 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.
Li(2)Na(2)NiP(6)O(18)·12H(2)O的晶体结构的特征在于存在具有椅式构象的六元P(6)O(18) (6-)磷酸环阴离子（内部对称-1）以及三种不同的阳离子，即Li(+)、Na(+)和Ni(2+)，以平衡阴离子电荷。除镍位于具有位点对称性2的特殊位置外，所有原子均处于一般位置。锂具有四面体环境（LiO(4)），钠和镍具有八面体环境[分别为NaO(6)和Ni(H(2)O)(6)]。P(6)O(18)环通过NaO(6)八面体和LiO(4)四面体的角共享相连，形成一个沿[010]方向有隧道的三维骨架，其中六配位的Ni(2+)阳离子位于隧道中。该结构通过O-H⋯O氢键网络得以稳定。
