Materials Data on HfTiSe4 by Materials Project
HfTiSe4 is trigonal omega-derived structured and crystallizes in the monoclinic P2/m space group. The structure is two-dimensional and consists of one HfTiSe4 sheet oriented in the (0, 0, 1) 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 TiSe6 octahedra. There are two shorter (2.66 Å) and four longer (2.67 Å) Hf–Se bond lengths. Ti4+ is bonded to six Se2- atoms to form TiSe6 octahedra that share edges with two equivalent TiSe6 octahedra and edges with four equivalent HfSe6 octahedra. There are two shorter (2.59 Å) and four longer (2.60 Å) Ti–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted T-shaped geometry to two equivalent Hf4+ and one Ti4+ atom. In the second Se2- site, Se2- is bonded in a distorted T-shaped geometry to one Hf4+ and two equivalent Ti4+ atoms.