DOI: 10.17188/1268769
title: Materials Data on Na2Cd(SiO3)2 by Materials Project

description: Na2Cd(SiO3)2 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.94 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one CdO6 octahedra. There are a spread of Na–O bond distances ranging from 2.31–2.48 Å. In the third Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.53–2.88 Å. In the fourth Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–3.01 Å. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six O2- atoms to form distorted CdO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.29–2.52 Å. In the second Cd2+ site, Cd2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cd–O bond distances ranging from 2.16–2.68 Å. In the third Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six SiO4 tetrahedra, a faceface with one NaO6 octahedra, and a faceface with one CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.32–2.37 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three CdO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–50°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three CdO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–55°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CdO6 octahedra, corners with two equivalent NaO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–52°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CdO6 octahedra, corners with two equivalent NaO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–47°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, three Cd2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to two Na1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, two Cd2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Cd2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, two Cd2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Cd2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Cd2+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Cd2+, and one Si4+ atom.