Materials Data on Ca3PbSe4 by Materials Project
Ca3PbSe4 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six Se2- atoms to form CaSe6 octahedra that share corners with six equivalent CaSe6 octahedra, edges with four equivalent PbSe6 octahedra, and edges with eight CaSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are two shorter (3.01 Å) and four longer (3.03 Å) Ca–Se bond lengths. In the second Ca2+ site, Ca2+ is bonded to six Se2- atoms to form CaSe6 octahedra that share corners with two equivalent CaSe6 octahedra, corners with four equivalent PbSe6 octahedra, edges with two equivalent PbSe6 octahedra, and edges with ten CaSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are four shorter (2.96 Å) and two longer (3.03 Å) Ca–Se bond lengths. Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with two equivalent PbSe6 octahedra, corners with four equivalent CaSe6 octahedra, edges with two equivalent PbSe6 octahedra, and edges with ten CaSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (3.03 Å) and four longer (3.09 Å) Pb–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to six Ca2+ atoms to form a mixture of edge and corner-sharing SeCa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to four Ca2+ and two equivalent Pb2+ atoms to form SeCa4Pb2 octahedra that share corners with six equivalent SeCa4Pb2 octahedra and edges with twelve SeCa6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third Se2- site, Se2- is bonded to four equivalent Ca2+ and two equivalent Pb2+ atoms to form a mixture of edge and corner-sharing SeCa4Pb2 octahedra. The corner-sharing octahedral tilt angles are 0°.