DOE OSTI2020
Ca(LuTe2)2 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. Ca2+ is bonded to six Te2- atoms to form CaTe6 octahedra that share corners with six equivalent LuTe6 octahedra, edges with two equivalent CaTe6 octahedra, and edges with six LuTe6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are two shorter (3.13 Å) and four longer (3.19 Å) Ca–Te bond lengths. There are two inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to six Te2- atoms to form LuTe6 octahedra that share corners with six equivalent CaTe6 octahedra, edges with two equivalent CaTe6 octahedra, and edges with six LuTe6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are two shorter (2.99 Å) and four longer (3.05 Å) Lu–Te bond lengths. In the second Lu3+ site, Lu3+ is bonded to six Te2- atoms to form LuTe6 octahedra that share edges with four equivalent CaTe6 octahedra and edges with six LuTe6 octahedra. There are four shorter (3.05 Å) and two longer (3.07 Å) Lu–Te bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to two equivalent Ca2+ and three Lu3+ atoms to form a mixture of corner and edge-sharing TeCa2Lu3 square pyramids. In the second Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Lu3+ atoms.