Materials Data on Sm6Si4S17 by Materials Project
Sm6Si4S17 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are six inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are a spread of Sm–S bond distances ranging from 2.85–3.26 Å. In the second Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.87–3.30 Å. In the third Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.75–3.29 Å. In the fourth Sm3+ site, Sm3+ is bonded to seven S2- atoms to form distorted SmS7 pentagonal bipyramids that share corners with two SiS4 tetrahedra and edges with two SiS4 tetrahedra. There are a spread of Sm–S bond distances ranging from 2.80–2.95 Å. In the fifth Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.84–3.22 Å. In the sixth Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.86–3.19 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Si–S bond distances ranging from 2.10–2.15 Å. In the second Si4+ site, Si4+ is bonded to four S2- atoms to form SiS4 tetrahedra that share an edgeedge with one SmS7 pentagonal bipyramid. There are a spread of Si–S bond distances ranging from 2.12–2.15 Å. In the third Si4+ site, Si4+ is bonded to four S2- atoms to form SiS4 tetrahedra that share a cornercorner with one SmS7 pentagonal bipyramid and an edgeedge with one SmS7 pentagonal bipyramid. There are a spread of Si–S bond distances ranging from 2.10–2.15 Å. In the fourth Si4+ site, Si4+ is bonded to four S2- atoms to form SiS4 tetrahedra that share a cornercorner with one SmS7 pentagonal bipyramid. There are a spread of Si–S bond distances ranging from 2.10–2.16 Å. There are seventeen inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to two Sm3+ and one Si4+ atom. In the second S2- site, S2- is bonded to three Sm3+ and one Si4+ atom to form distorted SSm3Si trigonal pyramids that share corners with two SSm3Si trigonal pyramids and an edgeedge with one SSm4 tetrahedra. In the third S2- site, S2- is bonded in a 3-coordinate geometry to two Sm3+ and one Si4+ atom. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the fifth S2- site, S2- is bonded in a distorted T-shaped geometry to two Sm3+ and one Si4+ atom. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Sm3+ and one Si4+ atom. In the seventh S2- site, S2- is bonded in a 1-coordinate geometry to four Sm3+ and one Si4+ atom. In the eighth S2- site, S2- is bonded in a 3-coordinate geometry to two Sm3+ and one Si4+ atom. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the eleventh S2- site, S2- is bonded in a 1-coordinate geometry to two Sm3+ and one Si4+ atom. In the twelfth S2- site, S2- is bonded to three Sm3+ and one Si4+ atom to form distorted SSm3Si trigonal pyramids that share a cornercorner with one SSm4 tetrahedra and corners with two SSm3Si trigonal pyramids. In the thirteenth S2- site, S2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the fourteenth S2- site, S2- is bonded to three Sm3+ and one Si4+ atom to form distorted SSm3Si trigonal pyramids that share corners with two SSm3Si trigonal pyramids and an edgeedge with one SSm4 tetrahedra. In the fifteenth S2- site, S2- is bonded to four Sm3+ atoms to form a mixture of distorted corner and edge-sharing SSm4 tetrahedra. In the sixteenth S2- site, S2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the seventeenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Sm3+ and one Si4+ atom.