Materials Data on Na6Bi2B4AsO16 by Materials Project
Na6B4Bi2AsO16 crystallizes in the cubic Fd-3 space group. The structure is three-dimensional. Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with eight equivalent NaO6 octahedra, edges with two equivalent BiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–84°. There are a spread of Na–O bond distances ranging from 2.43–2.55 Å. B is bonded in a trigonal planar geometry to three equivalent O atoms. All B–O bond lengths are 1.39 Å. Bi is bonded to six equivalent O atoms to form BiO6 octahedra that share edges with six equivalent NaO6 octahedra. All Bi–O bond lengths are 2.25 Å. As is bonded to four equivalent O atoms to form AsO4 tetrahedra that share edges with six equivalent NaO6 octahedra. All As–O bond lengths are 1.73 Å. There are two inequivalent O sites. In the first O site, O is bonded to three equivalent Na and one As atom to form edge-sharing ONa3As trigonal pyramids. In the second O site, O is bonded in a distorted single-bond geometry to two equivalent Na, one B, and one Bi atom.