Materials Data on Ca3Si4(SnO7)2 by Materials Project
Ca3Si4(SnO7)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.68 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.79 Å. There are two inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with four SiO4 tetrahedra and edges with two equivalent SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.28–2.55 Å. In the second Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with four SiO4 tetrahedra and edges with two equivalent SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 1.97–2.26 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SnO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SnO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–77°. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one Sn3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Sn3+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Sn3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Sn3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one Si4+ atom.