Materials Data on La2Si4CN6 by Materials Project

La2Si4N6C crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 1-coordinate geometry to eight N3- atoms. There are a spread of La–N bond distances ranging from 2.40–3.02 Å. In the second La3+ site, La3+ is bonded to seven N3- atoms to form distorted LaN7 pentagonal bipyramids that share corners with eight SiCN3 tetrahedra, edges with two equivalent LaN7 pentagonal bipyramids, and edges with three SiCN3 tetrahedra. There are a spread of La–N bond distances ranging from 2.48–2.78 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to one C4- and three N3- atoms to form SiCN3 tetrahedra that share corners with two equivalent LaN7 pentagonal bipyramids, corners with six SiCN3 tetrahedra, and an edgeedge with one LaN7 pentagonal bipyramid. The Si–C bond length is 1.92 Å. There is one shorter (1.71 Å) and two longer (1.76 Å) Si–N bond length. In the second Si4+ site, Si4+ is bonded to one C4- and three N3- atoms to form SiCN3 tetrahedra that share corners with two equivalent LaN7 pentagonal bipyramids and corners with six SiCN3 tetrahedra. The Si–C bond length is 1.95 Å. All Si–N bond lengths are 1.75 Å. In the third Si4+ site, Si4+ is bonded to one C4- and three N3- atoms to form SiCN3 tetrahedra that share corners with two equivalent LaN7 pentagonal bipyramids, corners with six SiCN3 tetrahedra, and an edgeedge with one LaN7 pentagonal bipyramid. The Si–C bond length is 1.95 Å. There are a spread of Si–N bond distances ranging from 1.74–1.78 Å. C4- is bonded in a tetrahedral geometry to four Si4+ atoms. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a 5-coordinate geometry to three La3+ and two Si4+ atoms. In the second N3- site, N3- is bonded in a 4-coordinate geometry to two La3+ and two equivalent Si4+ atoms. In the third N3- site, N3- is bonded in a 2-coordinate geometry to three equivalent La3+ and two Si4+ atoms. In the fourth N3- site, N3- is bonded in a 2-coordinate geometry to two La3+ and two Si4+ atoms.