DOE OSTI2020
Er2PbS4 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are six inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Er–S bond distances ranging from 2.70–2.77 Å. In the second Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of Er–S bond distances ranging from 2.68–2.75 Å. In the third Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Er–S bond distances ranging from 2.71–2.75 Å. In the fourth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 49–61°. There are a spread of Er–S bond distances ranging from 2.68–2.76 Å. In the fifth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of Er–S bond distances ranging from 2.69–2.77 Å. In the sixth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Er–S bond distances ranging from 2.70–2.75 Å. There are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pb–S bond distances ranging from 2.86–3.36 Å. In the second Pb2+ site, Pb2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pb–S bond distances ranging from 2.89–3.38 Å. In the third Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pb–S bond distances ranging from 3.03–3.52 Å. There are twelve inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to three Er3+ and two Pb2+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the fourth S2- site, S2- is bonded in a distorted trigonal pyramidal geometry to three Er3+ and one Pb2+ atom. In the fifth S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and two Pb2+ atoms. In the sixth S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the seventh S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Pb2+ atom. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the ninth S2- site, S2- is bonded in a 5-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the tenth S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms. In the eleventh S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and two Pb2+ atoms. In the twelfth S2- site, S2- is bonded in a 5-coordinate geometry to three Er3+ and two equivalent Pb2+ atoms.