Materials Data on HfTeSe4 by Materials Project
HfTeSe4 crystallizes in the monoclinic P2/m space group. The structure is two-dimensional and consists of one HfTeSe4 sheet oriented in the (1, 0, 0) direction. Hf4+ is bonded to six Se2- atoms to form HfSe6 octahedra that share edges with two equivalent HfSe6 octahedra and edges with four equivalent TeSe6 octahedra. There are two shorter (2.69 Å) and four longer (2.71 Å) Hf–Se bond lengths. Te4+ is bonded to six Se2- atoms to form TeSe6 octahedra that share edges with two equivalent TeSe6 octahedra and edges with four equivalent HfSe6 octahedra. All Te–Se bond lengths are 2.81 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Hf4+ and one Te4+ atom. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to one Hf4+ and two equivalent Te4+ atoms.