Materials Data on Ca5Sn7S19 by Materials Project
Ca5Sn7S19 crystallizes in the orthorhombic Pmmm space group. The structure is two-dimensional and consists of one Ca5Sn7S19 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ca–S bond distances ranging from 2.81–3.45 Å. In the second Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are one shorter (2.74 Å) and four longer (2.90 Å) Ca–S bond lengths. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight equivalent S2- atoms. All Ca–S bond lengths are 3.15 Å. There are four inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded in a 4-coordinate geometry to four S2- atoms. There are two shorter (2.56 Å) and two longer (2.59 Å) Sn–S bond lengths. In the second Sn4+ site, Sn4+ is bonded to six S2- atoms to form distorted corner-sharing SnS6 pentagonal pyramids. There are a spread of Sn–S bond distances ranging from 2.49–2.77 Å. In the third Sn4+ site, Sn4+ is bonded to six S2- atoms to form distorted corner-sharing SnS6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. There are a spread of Sn–S bond distances ranging from 2.55–2.71 Å. In the fourth Sn4+ site, Sn4+ is bonded to six S2- atoms to form distorted corner-sharing SnS6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.47 Å) and four longer (2.71 Å) Sn–S bond lengths. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to one Ca2+ and two equivalent Sn4+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Sn4+ atoms. In the third S2- site, S2- is bonded in a T-shaped geometry to one Ca2+ and two equivalent Sn4+ atoms. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Sn4+ atoms. In the fifth S2- site, S2- is bonded in a distorted T-shaped geometry to one Ca2+ and two equivalent Sn4+ atoms. In the sixth S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Sn4+ atoms. In the seventh S2- site, S2- is bonded in a distorted linear geometry to two equivalent Sn4+ atoms.