Materials Data on Sr4GeP4 by Materials Project
Sr4GeP4 crystallizes in the cubic P-43n space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six P3- atoms to form distorted SrP6 octahedra that share corners with six SrP6 octahedra, corners with three GeP4 tetrahedra, edges with twelve SrP6 octahedra, and a faceface with one GeP4 tetrahedra. The corner-sharing octahedra tilt angles range from 14–17°. There are a spread of Sr–P bond distances ranging from 3.10–3.26 Å. In the second Sr2+ site, Sr2+ is bonded to six P3- atoms to form distorted SrP6 octahedra that share corners with six equivalent SrP6 octahedra, corners with three equivalent GeP4 tetrahedra, edges with twelve SrP6 octahedra, and a faceface with one GeP4 tetrahedra. The corner-sharing octahedral tilt angles are 15°. There are three shorter (3.14 Å) and three longer (3.26 Å) Sr–P bond lengths. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four equivalent P3- atoms to form GeP4 tetrahedra that share corners with twelve SrP6 octahedra and faces with four equivalent SrP6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. All Ge–P bond lengths are 2.38 Å. In the second Ge4+ site, Ge4+ is bonded to four equivalent P3- atoms to form GeP4 tetrahedra that share corners with twelve equivalent SrP6 octahedra and faces with four equivalent SrP6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Ge–P bond lengths are 2.37 Å. There are two inequivalent P3- sites. In the first P3- site, P3- is bonded to six Sr2+ and one Ge4+ atom to form a mixture of distorted edge, corner, and face-sharing PSr6Ge pentagonal bipyramids. In the second P3- site, P3- is bonded to six Sr2+ and one Ge4+ atom to form a mixture of distorted edge, corner, and face-sharing PSr6Ge pentagonal bipyramids.