Fe${\mathrm{Nb}}_3$${\mathrm{Se}}_{10}$: A new structure type related to Nb${\mathrm{Se}}_3$

Employing single-crystal x-ray-diffraction techniques, the crystal structure of Fe${\mathrm{Nb}}_3$ ${\mathrm{Se}}_{10}$ was found to consist of two Nb${\mathrm{Se}}_6$ trigonal prismatic chains of the type found in Nb${\mathrm{Se}}_3$ and a double chain of edge-shared $M{\mathrm{Se}}_6$ octahedra, both running parallel to the monoclinic $b$ axis. The metal-atom disorder, critical to the interpretation of previously observed electronic properties, is confined to the octahedral chains.