Materials Data on Ba4GeP4 by Materials Project
Ba4GeP4 crystallizes in the cubic P-43n space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six P3- atoms to form distorted BaP6 octahedra that share corners with six BaP6 octahedra, corners with three GeP4 tetrahedra, edges with twelve BaP6 octahedra, and a faceface with one GeP4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–20°. There are a spread of Ba–P bond distances ranging from 3.31–3.41 Å. In the second Ba2+ site, Ba2+ is bonded to six P3- atoms to form distorted BaP6 octahedra that share corners with six equivalent BaP6 octahedra, corners with three equivalent GeP4 tetrahedra, edges with twelve BaP6 octahedra, and a faceface with one GeP4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–18°. There are three shorter (3.35 Å) and three longer (3.39 Å) Ba–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 BaP6 octahedra and faces with four equivalent BaP6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. All Ge–P bond lengths are 2.41 Å. In the second Ge4+ site, Ge4+ is bonded to four equivalent P3- atoms to form GeP4 tetrahedra that share corners with twelve equivalent BaP6 octahedra and faces with four equivalent BaP6 octahedra. The corner-sharing octahedral tilt angles are 52°. All Ge–P bond lengths are 2.39 Å. There are two inequivalent P3- sites. In the first P3- site, P3- is bonded in a 7-coordinate geometry to six Ba2+ and one Ge4+ atom. In the second P3- site, P3- is bonded to six Ba2+ and one Ge4+ atom to form a mixture of distorted edge, corner, and face-sharing PBa6Ge pentagonal bipyramids.