Materials Data on CaPb3Se4 by Materials Project
CaPb3Se4 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Ca2+ is bonded to six Se2- atoms to form CaSe6 octahedra that share corners with six equivalent PbSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with ten PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. All Ca–Se bond lengths are 3.03 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with six equivalent PbSe6 octahedra, edges with four equivalent CaSe6 octahedra, and edges with eight PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. All Pb–Se bond lengths are 3.09 Å. In the second Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with six equivalent CaSe6 octahedra, edges with two equivalent CaSe6 octahedra, and edges with ten PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. All Pb–Se bond lengths are 3.15 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Ca2+ and five Pb2+ atoms to form a mixture of edge and corner-sharing SeCaPb5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to two equivalent Ca2+ and four Pb2+ atoms to form SeCa2Pb4 octahedra that share corners with six equivalent SeCa2Pb4 octahedra and edges with twelve SeCaPb5 octahedra. The corner-sharing octahedral tilt angles are 0°.