Materials Data on ErCuPbS3 by Materials Project
ErCuPbS3 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with two equivalent ErS6 octahedra, edges with two equivalent ErS6 octahedra, and edges with four equivalent CuS4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are four shorter (2.71 Å) and two longer (2.75 Å) Er–S bond lengths. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent CuS4 tetrahedra and edges with four equivalent ErS6 octahedra. There are a spread of Cu–S bond distances ranging from 2.32–2.40 Å. Pb2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pb–S bond distances ranging from 2.98–3.29 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Er3+, one Cu1+, and three equivalent Pb2+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Er3+, one Cu1+, and two equivalent Pb2+ atoms. In the third S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Er3+, two equivalent Cu1+, and two equivalent Pb2+ atoms.