Materials Data on Sr4CN4 by Materials Project
Sr4CN4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Sr–N bond distances ranging from 2.56–2.87 Å. In the second 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 2.52–2.71 Å. In the third Sr2+ site, Sr2+ is bonded to five N3- atoms to form distorted SrN5 square pyramids that share a cornercorner with one SrN6 octahedra, edges with two equivalent SrN6 octahedra, and edges with two equivalent SrN5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Sr–N bond distances ranging from 2.49–3.03 Å. In the fourth Sr2+ site, Sr2+ is bonded to six N3- atoms to form SrN6 octahedra that share a cornercorner with one SrN5 square pyramid, edges with four equivalent SrN6 octahedra, and edges with two equivalent SrN5 square pyramids. There are a spread of Sr–N bond distances ranging from 2.69–2.88 Å. C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.24 Å) and one longer (1.25 Å) C–N bond length. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted single-bond geometry to four Sr2+ and one C4+ atom. In the second N3- site, N3- is bonded to six Sr2+ atoms to form a mixture of edge and corner-sharing NSr6 octahedra. The corner-sharing octahedra tilt angles range from 6–52°. In the third N3- site, N3- is bonded to six Sr2+ atoms to form a mixture of edge and corner-sharing NSr6 octahedra. The corner-sharing octahedra tilt angles range from 6–52°. In the fourth N3- site, N3- is bonded in a 1-coordinate geometry to four Sr2+ and one C4+ atom.