Materials Data on Ba3Al3P5 by Materials Project

Abstract

Ba3Al3P5 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven P3- atoms. There are a spread of Ba–P bond distances ranging from 3.18–3.80 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six P3- atoms. There are three shorter (3.21 Å) and three longer (3.67 Å) Ba–P bond lengths. In the third Ba2+ site, Ba2+ is bonded to six equivalent P3- atoms to form distorted BaP6 octahedra that share corners with twelve equivalent AlP4 tetrahedra and edges with three equivalent AlP4 tetrahedra. All Ba–P bond lengths are 3.19 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four P3- atoms to form AlP4 tetrahedra that share corners with two equivalent AlP4 tetrahedra, an edgeedge with one BaP6 octahedra, and edges with two equivalent AlP4 tetrahedra. There are two shorter (2.39 Å) and two longer (2.46 Å) Al–P bond lengths. In the second Al3+ site, Al3+ is bonded to four P3- atoms to form AlP4 tetrahedra that share corners with two equivalent BaP6 octahedra, corners with two AlP4 tetrahedra, and edges with two AlP4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–65°. There are a spread of Al–P bond distances ranging from 2.34–2.48 Å. There are three inequivalent P3- sites. In the first P3- site, P3- is bonded in a 2-coordinate geometry to four equivalent Ba2+ and two equivalent Al3+ atoms. In the second P3- site, P3- is bonded in a 7-coordinate geometry to four Ba2+ and three Al3+ atoms. In the third P3- site, P3- is bonded in a 6-coordinate geometry to four Ba2+ and two Al3+ atoms.