Materials Data on TmTlSe2 by Materials Project
TmTlSe2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Tm3+ is bonded to six equivalent Se2- atoms to form TmSe6 octahedra that share corners with six equivalent TlSe6 octahedra, edges with six equivalent TmSe6 octahedra, and edges with six equivalent TlSe6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Tm–Se bond lengths are 2.86 Å. Tl1+ is bonded to six equivalent Se2- atoms to form distorted TlSe6 octahedra that share corners with six equivalent TmSe6 octahedra, edges with six equivalent TmSe6 octahedra, and edges with six equivalent TlSe6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Tl–Se bond lengths are 3.34 Å. Se2- is bonded to three equivalent Tm3+ and three equivalent Tl1+ atoms to form a mixture of distorted corner and edge-sharing SeTm3Tl3 octahedra. The corner-sharing octahedral tilt angles are 0°.