DOE OSTI2020
BaP3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten P+0.67- atoms. There are a spread of Ba–P bond distances ranging from 3.30–3.66 Å. There are three inequivalent P+0.67- sites. In the first P+0.67- site, P+0.67- is bonded to four equivalent Ba2+ and two P+0.67- atoms to form distorted PBa4P2 octahedra that share corners with sixteen PBa4P2 octahedra, corners with four equivalent PBa2P3 square pyramids, edges with five PBa4P2 octahedra, edges with three equivalent PBa2P3 square pyramids, and a faceface with one PBa4P2 octahedra. The corner-sharing octahedra tilt angles range from 19–107°. There are one shorter (2.18 Å) and one longer (2.22 Å) P–P bond lengths. In the second P+0.67- site, P+0.67- is bonded to two equivalent Ba2+ and three P+0.67- atoms to form distorted PBa2P3 square pyramids that share corners with ten PBa4P2 octahedra, corners with two equivalent PBa2P3 square pyramids, and edges with five PBa4P2 octahedra. The corner-sharing octahedra tilt angles range from 27–142°. There are one shorter (2.22 Å) and one longer (2.25 Å) P–P bond lengths. In the third P+0.67- site, P+0.67- is bonded to four equivalent Ba2+ and two P+0.67- atoms to form distorted PBa4P2 octahedra that share corners with twelve PBa4P2 octahedra, corners with six equivalent PBa2P3 square pyramids, edges with seven PBa4P2 octahedra, edges with two equivalent PBa2P3 square pyramids, and a faceface with one PBa4P2 octahedra. The corner-sharing octahedra tilt angles range from 19–107°.