DOI: 10.17188/1719743
title: Materials Data on Er2Si4CN6 by Materials Project

description: Er2Si4CN6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six N3- atoms to form distorted ErN6 pentagonal pyramids that share corners with ten SiCN3 tetrahedra, an edgeedge with one ErN6 pentagonal pyramid, and an edgeedge with one SiCN3 tetrahedra. There are a spread of Er–N bond distances ranging from 2.32–2.60 Å. In the second Er3+ site, Er3+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of Er–N bond distances ranging from 2.31–2.95 Å. There are four 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 ErN6 pentagonal pyramids and corners with six SiCN3 tetrahedra. The Si–C bond length is 1.91 Å. There are a spread of Si–N bond distances ranging from 1.74–1.77 Å. 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 ErN6 pentagonal pyramids, corners with six SiCN3 tetrahedra, and an edgeedge with one ErN6 pentagonal pyramid. The Si–C bond length is 1.90 Å. There are a spread of Si–N bond distances ranging from 1.75–1.77 Å. In the third Si4+ site, Si4+ is bonded to one C4- and three N3- atoms to form SiCN3 tetrahedra that share corners with three equivalent ErN6 pentagonal pyramids and corners with six SiCN3 tetrahedra. The Si–C bond length is 1.87 Å. There is two shorter (1.75 Å) and one longer (1.76 Å) Si–N bond length. In the fourth Si4+ site, Si4+ is bonded to one C4- and three N3- atoms to form SiCN3 tetrahedra that share corners with three equivalent ErN6 pentagonal pyramids and corners with six SiCN3 tetrahedra. The Si–C bond length is 1.90 Å. There are a spread of Si–N bond distances ranging from 1.73–1.76 Å. C4- is bonded to four Si4+ atoms to form CSi4 tetrahedra that share corners with six NEr2Si2 tetrahedra and corners with four NEr2Si2 trigonal pyramids. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded to two equivalent Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with two equivalent CSi4 tetrahedra, corners with four NEr2Si2 tetrahedra, corners with four NEr2Si2 trigonal pyramids, an edgeedge with one NEr2Si2 tetrahedra, and an edgeedge with one NEr2Si2 trigonal pyramid. In the second N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with two equivalent CSi4 tetrahedra, corners with six NEr2Si2 tetrahedra, corners with three NEr2Si2 trigonal pyramids, and an edgeedge with one NEr2Si2 trigonal pyramid. In the third N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 trigonal pyramids that share corners with two equivalent CSi4 tetrahedra, corners with six NEr2Si2 tetrahedra, a cornercorner with one NEr2Si2 trigonal pyramid, an edgeedge with one NEr2Si2 tetrahedra, and an edgeedge with one NEr2Si2 trigonal pyramid. In the fourth N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 trigonal pyramids that share corners with two equivalent CSi4 tetrahedra, corners with six NEr2Si2 tetrahedra, a cornercorner with one NEr2Si2 trigonal pyramid, an edgeedge with one NEr2Si2 tetrahedra, and an edgeedge with one NEr2Si2 trigonal pyramid. In the fifth N3- site, N3- is bonded in a distorted trigonal planar geometry to two Er3+ and two Si4+ atoms. In the sixth N3- site, N3- is bonded to two equivalent Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with two equivalent CSi4 tetrahedra, corners with four NEr2Si2 tetrahedra, corners with five NEr2Si2 trigonal pyramids, and an edgeedge with one NEr2Si2 tetrahedra.