Materials Data on Ce5(SiN3)3 by Materials Project
Ce5Si3N9 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are four inequivalent Ce3+ sites. In the first Ce3+ site, Ce3+ is bonded to seven N3- atoms to form distorted CeN7 pentagonal bipyramids that share corners with two equivalent SiN4 tetrahedra, edges with two equivalent CeN6 octahedra, and edges with four SiN4 tetrahedra. There are a spread of Ce–N bond distances ranging from 2.41–2.66 Å. In the second Ce3+ site, Ce3+ is bonded in a 1-coordinate geometry to seven N3- atoms. There are a spread of Ce–N bond distances ranging from 2.32–2.92 Å. In the third Ce3+ site, Ce3+ is bonded to six N3- atoms to form distorted CeN6 octahedra that share corners with six SiN4 tetrahedra, an edgeedge with one CeN6 octahedra, and edges with two equivalent CeN7 pentagonal bipyramids. There are a spread of Ce–N bond distances ranging from 2.37–2.76 Å. In the fourth Ce3+ site, Ce3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are a spread of Ce–N bond distances ranging from 2.40–3.05 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with three SiN4 tetrahedra and edges with two equivalent CeN7 pentagonal bipyramids. There are a spread of Si–N bond distances ranging from 1.71–1.73 Å. In the second Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with four equivalent CeN6 octahedra, corners with two equivalent CeN7 pentagonal bipyramids, and a cornercorner with one SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–74°. There are a spread of Si–N bond distances ranging from 1.74–1.77 Å. In the third Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with two equivalent CeN6 octahedra, corners with two equivalent SiN4 tetrahedra, and edges with two equivalent CeN7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. There is two shorter (1.72 Å) and two longer (1.74 Å) Si–N bond length. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded in a 6-coordinate geometry to five Ce3+ and one Si4+ atom. In the second N3- site, N3- is bonded in a distorted linear geometry to three Ce3+ and two Si4+ atoms. In the third N3- site, N3- is bonded in a 6-coordinate geometry to five Ce3+ and one Si4+ atom. In the fourth N3- site, N3- is bonded in a 1-coordinate geometry to four Ce3+ and one Si4+ atom. In the fifth N3- site, N3- is bonded in a distorted trigonal bipyramidal geometry to four Ce3+ and one Si4+ atom. In the sixth N3- site, N3- is bonded in a 2-coordinate geometry to three Ce3+ and two Si4+ atoms.