A new compound was found in the ternary system K2O–Cr2O3–Nb2O5, Chemical analyses show that the compound formula is K6CrNb15O42. The structure was solved using direct method and Fourier techniques; it crystallizes in the hexagonal system with unit cell parameters a = 9.126(3) Å, c = 12.068(3) Å, V = 870.4(5) Å3, and space group P63/mcm, Z = 1. Of the 829 unique reflections measured by counter techniques 448 with I > 3σ(I) were used in the least-square refinement of the model to R = 0.034 (Rw = 0.044). The structure of K6CrNb15O42 may be described as consisting of corner-shared and edge-shared octahedra the ring units composed of six octahedra share corners along the c-axis to form a kind of hexagonal column octahedra chain, which is the first one discovered in niobates.
Zeitschrift für Kristallographie – Crystalline Materials offers a place for researchers to present results of their crystallographic studies. The journal includes theoretical as well as experimental research. It publishes Original Papers, Letters and Review Articles in manifold areas of crystallography.