Une nouvelle structure à tunnels: KxVxMo1?xO3 (x = 0.13)

The crystal structure of the hexagonal phase K_xV_xMo_1?xO₃ (x = 0.13) has been determined by single crystal X-ray analysis. The space group is P6₃. The parameters are a = 10.481 Å and c = 3.701 Å. The structure is formed by triple chains of octahedra sharing corners and parallel to the Oz axis. Each triple chain shares edges with three other chains.Potassium is inserted in the large tunnels. The reliability factor is R = 0.045 on the base of 158 observed reflexions. The Rb_xV_xMo_1?xO₃ and Cs_xV_xMo_1?xO₃ phases (0.12 ? x ? 0.14) are isostructural with K_xV_xMo_1?xO₃.