Single crystal growth and structure determination of Rb_1.5Mn₈O₁₆ hollandite

抄録

Single crystals of Rb_1.5Mn₈O₁₆ were grown under the hydrothermal conditions of 450°C and 0.2GPa. The structure was tetragonal (I4/m); a=9.915(9)Å, c=2.866(3)Å and Z=1. The X-ray structure analysis was performed using the 656 independent reflections to R=0.088 and R_w=0.054. The determined structure adopts hollandite type characterized by the 2×2 tunnel. It is noted the electron density distribution of Rb⁺ in the tunnel was elongated along the c-axis, suggesting the distribution of Rb⁺ over the special position (2b).