DOI: 10.17188/1271600
title: Materials Data on Na5Bi2As5O18 by Materials Project

description: Na5Bi2As5O18 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, corners with six AsO4 tetrahedra, an edgeedge with one NaO6 octahedra, and edges with two equivalent BiO6 octahedra. The corner-sharing octahedral tilt angles are 76°. There are a spread of Na–O bond distances ranging from 2.28–2.67 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.24–2.92 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one BiO6 octahedra, corners with six AsO4 tetrahedra, and a faceface with one BiO6 octahedra. The corner-sharing octahedral tilt angles are 74°. There are a spread of Na–O bond distances ranging from 2.35–2.71 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two NaO6 octahedra, corners with six AsO4 tetrahedra, an edgeedge with one NaO6 octahedra, and edges with two equivalent BiO6 octahedra. The corner-sharing octahedra tilt angles range from 74–76°. There are a spread of Na–O bond distances ranging from 2.34–2.88 Å. In the fifth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.40–3.02 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six O2- atoms to form distorted BiO6 octahedra that share a cornercorner with one NaO6 octahedra, corners with six AsO4 tetrahedra, and a faceface with one NaO6 octahedra. The corner-sharing octahedral tilt angles are 74°. There are a spread of Bi–O bond distances ranging from 2.24–2.55 Å. In the second Bi3+ site, Bi3+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six AsO4 tetrahedra and edges with four NaO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.34–2.47 Å. There are five inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two BiO6 octahedra, corners with five NaO6 octahedra, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. There are a spread of As–O bond distances ranging from 1.68–1.83 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent BiO6 octahedra, corners with four NaO6 octahedra, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–68°. There are a spread of As–O bond distances ranging from 1.69–1.79 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three NaO6 octahedra, corners with three BiO6 octahedra, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–66°. There are a spread of As–O bond distances ranging from 1.70–1.79 Å. In the fourth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three NaO6 octahedra and corners with four BiO6 octahedra. The corner-sharing octahedra tilt angles range from 41–66°. There is three shorter (1.72 Å) and one longer (1.74 Å) As–O bond length. In the fifth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one BiO6 octahedra, corners with three NaO6 octahedra, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of As–O bond distances ranging from 1.69–1.81 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+, one Bi3+, and one As5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one As5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Bi3+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two As5+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi3+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Bi3+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Bi3+, and one As5+ atom. In the ninth O2- site, O2- is bonded to three Na1+ and one As5+ atom to form distorted edge-sharing ONa3As trigonal pyramids. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Bi3+, and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+ and one As5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Bi3+, and one As5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Bi3+, and one As5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Bi3+, and one As5+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Bi3+, and one As5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Bi3+, and one As5+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two As5+ atoms. In the eighteenth O2- site, O2- is bonded to two Na1+, one Bi3+, and one As5+ atom to form distorted edge-sharing ONa2BiAs trigonal pyramids.