DOI: 10.17188/1707167
title: Materials Data on Er6Si11N20O by Materials Project

description: Er6Si11N20O crystallizes in the trigonal P31c 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 ErN6 octahedra that share corners with two equivalent ErN6 octahedra, a cornercorner with one ErN5O pentagonal pyramid, corners with eight SiN4 tetrahedra, a cornercorner with one SiN3O trigonal pyramid, edges with two equivalent ErN5O pentagonal pyramids, and an edgeedge with one SiN4 tetrahedra. The corner-sharing octahedral tilt angles are 71°. There are a spread of Er–N bond distances ranging from 2.38–2.55 Å. In the second Er3+ site, Er3+ is bonded to five N3- and one O2- atom to form distorted ErN5O pentagonal pyramids that share a cornercorner with one ErN6 octahedra, corners with two equivalent ErN5O pentagonal pyramids, corners with nine SiN4 tetrahedra, edges with two equivalent ErN6 octahedra, and an edgeedge with one SiN3O trigonal pyramid. The corner-sharing octahedral tilt angles are 91°. There are a spread of Er–N bond distances ranging from 2.42–2.50 Å. The Er–O bond length is 2.28 Å. There are five inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with six equivalent ErN6 octahedra, corners with three equivalent ErN5O pentagonal pyramids, and corners with three equivalent SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 63–70°. There is one shorter (1.75 Å) and three longer (1.77 Å) Si–N bond length. In the second Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share a cornercorner with one ErN6 octahedra, corners with three equivalent ErN5O pentagonal pyramids, corners with four SiN4 tetrahedra, a cornercorner with one SiN3O trigonal pyramid, and an edgeedge with one ErN6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are a spread of Si–N bond distances ranging from 1.74–1.79 Å. In the third Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with two equivalent ErN6 octahedra, corners with two equivalent ErN5O pentagonal pyramids, and corners with six SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 69–71°. There are a spread of Si–N bond distances ranging from 1.74–1.76 Å. In the fourth Si4+ site, Si4+ is bonded to three equivalent N3- and one O2- atom to form SiN3O trigonal pyramids that share corners with three equivalent ErN6 octahedra, corners with three equivalent SiN4 tetrahedra, and edges with three equivalent ErN5O pentagonal pyramids. The corner-sharing octahedral tilt angles are 49°. All Si–N bond lengths are 1.71 Å. The Si–O bond length is 1.82 Å. In the fifth Si4+ site, Si4+ is bonded to four N3- atoms to form SiN4 tetrahedra that share corners with three equivalent ErN6 octahedra, corners with three equivalent ErN5O pentagonal pyramids, and corners with five SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 68–80°. There is three shorter (1.75 Å) and one longer (1.76 Å) Si–N bond length. There are eight inequivalent N3- sites. In the first N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with nine NEr2Si2 tetrahedra, a cornercorner with one OEr3Si trigonal pyramid, and corners with three equivalent NEr2Si2 trigonal pyramids. In the second N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with six NEr2Si2 tetrahedra, a cornercorner with one OEr3Si trigonal pyramid, and corners with three equivalent NEr2Si2 trigonal pyramids. 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 eight NEr2Si2 tetrahedra, a cornercorner with one OEr3Si trigonal pyramid, and an edgeedge with one NEr2Si2 tetrahedra. In the fourth N3- site, N3- is bonded to three equivalent Er3+ and one Si4+ atom to form corner-sharing NEr3Si tetrahedra. In the fifth N3- site, N3- is bonded in a trigonal non-coplanar geometry to three equivalent Si4+ atoms. In the sixth N3- site, N3- is bonded in a 4-coordinate geometry to two Er3+ and two Si4+ atoms. In the seventh N3- site, N3- is bonded to two Er3+ and two Si4+ atoms to form distorted NEr2Si2 tetrahedra that share corners with seven NEr2Si2 tetrahedra, a cornercorner with one NEr2Si2 trigonal pyramid, a cornercorner with one OEr3Si trigonal pyramid, and an edgeedge with one NEr2Si2 trigonal pyramid. In the eighth N3- site, N3- is bonded in a trigonal planar geometry to three Si4+ atoms. O2- is bonded to three equivalent Er3+ and one Si4+ atom to form OEr3Si trigonal pyramids that share corners with nine NEr2Si2 tetrahedra and corners with three equivalent NEr2Si2 trigonal pyramids.