Materials Data on Er3CuSnS7 by Materials Project

Er3CuSnS7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with six ErS7 pentagonal bipyramids, corners with two equivalent SnS4 tetrahedra, edges with four ErS7 pentagonal bipyramids, and an edgeedge with one SnS4 tetrahedra. There are a spread of Er–S bond distances ranging from 2.70–3.03 Å. In the second Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with six ErS7 pentagonal bipyramids, corners with two equivalent SnS4 tetrahedra, edges with four ErS7 pentagonal bipyramids, and an edgeedge with one SnS4 tetrahedra. There are a spread of Er–S bond distances ranging from 2.70–3.03 Å. In the third Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with six ErS7 pentagonal bipyramids, corners with two equivalent SnS4 tetrahedra, edges with four ErS7 pentagonal bipyramids, and an edgeedge with one SnS4 tetrahedra. There are a spread of Er–S bond distances ranging from 2.70–3.03 Å. Cu1+ is bonded in a trigonal planar geometry to three S2- atoms. There are two shorter (2.22 Å) and one longer (2.23 Å) Cu–S bond lengths. Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share corners with six ErS7 pentagonal bipyramids and edges with three ErS7 pentagonal bipyramids. There are one shorter (2.39 Å) and three longer (2.42 Å) Sn–S bond lengths. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Cu1+ atom. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Cu1+ atom. In the third S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Cu1+ atom. In the fourth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Sn4+ atom. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Sn4+ atom. In the seventh S2- site, S2- is bonded in a tetrahedral geometry to three Er3+ and one Sn4+ atom.