Materials Data on Tm5Te4Se by Materials Project
Tm5Te4Se is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Tm sites. In the first Tm site, Tm is bonded to six Te atoms to form TmTe6 octahedra that share corners with six TmTe4Se2 octahedra and edges with twelve TmTe6 octahedra. The corner-sharing octahedra tilt angles range from 10–11°. All Tm–Te bond lengths are 3.03 Å. In the second Tm site, Tm is bonded to four Te and two equivalent Se atoms to form a mixture of edge and corner-sharing TmTe4Se2 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are one shorter (3.09 Å) and three longer (3.12 Å) Tm–Te bond lengths. Both Tm–Se bond lengths are 2.79 Å. In the third Tm site, Tm is bonded to five Te and one Se atom to form a mixture of distorted edge and corner-sharing TmTe5Se octahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are a spread of Tm–Te bond distances ranging from 3.04–3.18 Å. The Tm–Se bond length is 2.75 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded to six Tm atoms to form TeTm6 octahedra that share a cornercorner with one SeTm6 octahedra, corners with five TeTm6 octahedra, edges with two equivalent SeTm6 octahedra, and edges with ten TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 0–14°. In the second Te site, Te is bonded to six Tm atoms to form TeTm6 octahedra that share corners with two equivalent SeTm6 octahedra, corners with four TeTm6 octahedra, edges with three equivalent SeTm6 octahedra, and edges with nine TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 0–14°. Se is bonded to six Tm atoms to form SeTm6 octahedra that share corners with six TeTm6 octahedra, edges with two equivalent SeTm6 octahedra, and edges with ten TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°.