Materials Data on Ca(HoSe2)2 by Materials Project
Ca(HoSe2)2 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. Ca2+ is bonded to six Se2- atoms to form CaSe6 octahedra that share corners with six equivalent HoSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with six HoSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are two shorter (2.95 Å) and four longer (3.00 Å) Ca–Se bond lengths. There are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six Se2- atoms to form HoSe6 octahedra that share edges with four equivalent CaSe6 octahedra and edges with six HoSe6 octahedra. There are four shorter (2.86 Å) and two longer (2.87 Å) Ho–Se bond lengths. In the second Ho3+ site, Ho3+ is bonded to six Se2- atoms to form HoSe6 octahedra that share corners with six equivalent CaSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with six HoSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are two shorter (2.82 Å) and four longer (2.89 Å) Ho–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ho3+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Ca2+ and three Ho3+ atoms to form a mixture of corner and edge-sharing SeCa2Ho3 square pyramids.