Materials Data on Sr2FeN2 by Materials Project
Sr2FeN2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to four N3- atoms to form distorted SrN4 trigonal pyramids that share a cornercorner with one SrN6 octahedra, corners with three equivalent SrN4 tetrahedra, and edges with two equivalent SrN6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Sr–N bond distances ranging from 2.62–2.73 Å. In the second Sr2+ site, Sr2+ is bonded to six N3- atoms to form SrN6 octahedra that share a cornercorner with one SrN4 tetrahedra, a cornercorner with one SrN4 trigonal pyramid, edges with two equivalent SrN6 octahedra, edges with two equivalent SrN4 tetrahedra, and edges with two equivalent SrN4 trigonal pyramids. There are a spread of Sr–N bond distances ranging from 2.60–2.78 Å. In the third Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to four N3- atoms. There are a spread of Sr–N bond distances ranging from 2.56–2.75 Å. In the fourth Sr2+ site, Sr2+ is bonded in a rectangular see-saw-like geometry to four N3- atoms. There are a spread of Sr–N bond distances ranging from 2.63–2.69 Å. In the fifth Sr2+ site, Sr2+ is bonded to four N3- atoms to form distorted SrN4 tetrahedra that share a cornercorner with one SrN6 octahedra, corners with three equivalent SrN4 trigonal pyramids, and edges with two equivalent SrN6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are a spread of Sr–N bond distances ranging from 2.61–2.72 Å. There are three inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded in a linear geometry to two equivalent N3- atoms. Both Fe–N bond lengths are 1.85 Å. In the second Fe2+ site, Fe2+ is bonded in a distorted trigonal planar geometry to three N3- atoms. There is one shorter (1.82 Å) and two longer (1.87 Å) Fe–N bond length. In the third Fe2+ site, Fe2+ is bonded in a distorted trigonal planar geometry to three N3- atoms. There are a spread of Fe–N bond distances ranging from 1.77–1.83 Å. There are five inequivalent N3- sites. In the first N3- site, N3- is bonded to five Sr2+ and one Fe2+ atom to form distorted NSr5Fe octahedra that share corners with eleven NSr5Fe octahedra, corners with three equivalent NSr3Fe2 trigonal bipyramids, and an edgeedge with one NSr5Fe octahedra. The corner-sharing octahedra tilt angles range from 0–63°. In the second N3- site, N3- is bonded to five Sr2+ and one Fe2+ atom to form distorted NSr5Fe octahedra that share corners with four NSr5Fe octahedra, corners with three equivalent NSr3Fe2 trigonal bipyramids, edges with six NSr5Fe octahedra, and an edgeedge with one NSr3Fe2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 14–61°. In the third N3- site, N3- is bonded to three Sr2+ and two equivalent Fe2+ atoms to form distorted NSr3Fe2 trigonal bipyramids that share corners with seven NSr5Fe octahedra, edges with three NSr5Fe octahedra, and an edgeedge with one NSr3Fe2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 20–76°. In the fourth N3- site, N3- is bonded to five Sr2+ and one Fe2+ atom to form distorted NSr5Fe octahedra that share corners with six NSr5Fe octahedra, a cornercorner with one NSr3Fe2 trigonal bipyramid, edges with six NSr5Fe octahedra, and an edgeedge with one NSr3Fe2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 8–63°. In the fifth N3- site, N3- is bonded to four Sr2+ and two equivalent Fe2+ atoms to form distorted NSr4Fe2 octahedra that share corners with six NSr5Fe octahedra, edges with five NSr5Fe octahedra, and an edgeedge with one NSr3Fe2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 8–62°.