Crystal structure of triple molybdate in the Rb2MoO4—Nd2(MoO4)3—Zr(MoO4)2 system

Using X-ray phase analysis, the Rb 2 MoO 4 —Nd 2 (MoO 4 ) 3 —Zr(MoO 4 ) 2 ternary salt system is studied. The crystals of rubidium-neodymium-zirconium triple molybdate are grown by solution-melt crystallization under spontaneous nucleation. According to the X-ray diffraction data (automatic X8 APEX diffractometer, MoK 6h radiation, 1345 F(hklit), R = 0.0356), the crystal structure and its composition is determined: Rb 4.7 Nd 0.7 Zr 1.3 (MoO 4 ) 6 . The sizes of the trigonal unit cell are as follows: a = b= 10.7561(2) A, c = 38.7790(12) A, V= 3885.41(16) A 3 , Z= 6, R3c space group. The three-dimensional mixed framework structure consists of Mo tetrahedra and two types of octahedra: (Nd,Zr)O 6 . The distribution of Nd 3+ and Zr 4+ cations over two crystallographic sites is also refined. Two types of rubidium atoms are located in large cavities of the framework.