Materials Data on Sr7GeN6 by Materials Project

Abstract

Sr7GeN6 crystallizes in the orthorhombic Pbcn 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 2.53–3.19 Å. In the second 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 2.54–3.11 Å. In the third Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to four N3- atoms. There are two shorter (2.64 Å) and two longer (2.76 Å) Sr–N bond lengths. In the fourth Sr2+ site, Sr2+ is bonded to five N3- atoms to form distorted SrN5 trigonal bipyramids that share a cornercorner with one GeN4 tetrahedra, an edgeedge with one GeN4 tetrahedra, and edges with two equivalent SrN5 trigonal bipyramids. There are a spread of Sr–N bond distances ranging from 2.50–2.95 Å. Ge4+ is bonded to four N3- atoms to form GeN4 tetrahedra that share corners with two equivalent SrN5 trigonal bipyramids and edges with two equivalent SrN5 trigonal bipyramids. There is two shorter (1.93 Å) and two longer (1.95 Å) Ge–N bond length. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a 7-coordinate geometry to six Sr2+ and one Ge4+ atom. In the second N3- site, N3- is bonded to five Sr2+ and one Ge4+ atom to form distorted NSr5Ge octahedra that share corners with two equivalent NSr5Ge octahedra, corners with four equivalent NSr6 pentagonal pyramids, an edgeedge with one NSr5Ge octahedra, and edges with two equivalent NSr6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 67°. In the third N3- site, N3- is bonded to six Sr2+ atoms to form distorted NSr6 pentagonal pyramids that share corners with four equivalent NSr5Ge octahedra, edges with two equivalent NSr5Ge octahedra, and edges with three equivalent NSr6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 25–72°.