DOI: 10.17188/1321361
title: Materials Data on Ca(SnO2)2 by Materials Project

description: Ca(SnO2)2 is Ilmenite-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine SnO6 octahedra. The corner-sharing octahedra tilt angles range from 52–69°. There are a spread of Ca–O bond distances ranging from 2.23–2.50 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are two shorter (2.39 Å) and four longer (2.44 Å) Ca–O bond lengths. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four SnO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.35–2.42 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.35–2.44 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four equivalent SnO6 octahedra. There are two shorter (2.34 Å) and four longer (2.42 Å) Ca–O bond lengths. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five SnO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.41 Å. There are nine inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four SnO4 tetrahedra, edges with three CaO6 octahedra, and edges with three SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.09–2.19 Å. In the second Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–74°. There are a spread of Sn–O bond distances ranging from 2.13–2.71 Å. In the third Sn3+ site, Sn3+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.29–2.72 Å. In the fourth Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six SnO4 tetrahedra, edges with two equivalent SnO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.10–2.14 Å. In the fifth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 52–74°. There are a spread of Sn–O bond distances ranging from 2.13–2.72 Å. In the sixth Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five SnO4 tetrahedra, edges with three CaO6 octahedra, and edges with three SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.10–2.18 Å. In the seventh Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–73°. There are a spread of Sn–O bond distances ranging from 2.13–2.71 Å. In the eighth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–74°. There are a spread of Sn–O bond distances ranging from 2.14–2.71 Å. In the ninth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine SnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–75°. There are a spread of Sn–O bond distances ranging from 2.10–2.77 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with five OCa2Sn2 tetrahedra, a cornercorner with one OSn4 trigonal pyramid, and an edgeedge with one OCa2Sn2 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Sn3+ atoms. In the fourth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCa2Sn2 tetrahedra. In the fifth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the seventh O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with eight OCa2Sn2 tetrahedra and edges with two OCaSn3 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the ninth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the tenth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with five OCa2Sn2 tetrahedra, a cornercorner with one OSn4 trigonal pyramid, and edges with two OCa2Sn2 tetrahedra. In the eleventh O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the twelfth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with nine OCa2Sn2 tetrahedra and edges with two OCaSn3 tetrahedra. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two equivalent Sn3+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the fifteenth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form distorted OCaSn3 tetrahedra that share corners with five OCa2Sn2 tetrahedra, corners with two equivalent OSn4 trigonal pyramids, and edges with two equivalent OCa2Sn2 tetrahedra. In the sixteenth O2- site, O2- is bonded to four Sn3+ atoms to form distorted corner-sharing OSn4 trigonal pyramids. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms.