DOI: 10.17188/1708296
title: Materials Data on Na2(BiO2)21 by Materials Project

description: Na2(BiO2)21 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to eight O2- atoms to form NaO8 hexagonal bipyramids that share edges with two equivalent BiO8 hexagonal bipyramids and edges with six BiO6 octahedra. There are a spread of Na–O bond distances ranging from 2.53–2.76 Å. There are ten inequivalent Bi+3.90+ sites. In the first Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra, edges with two equivalent NaO8 hexagonal bipyramids, and edges with four equivalent BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 48–52°. All Bi–O bond lengths are 2.16 Å. In the second Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra, an edgeedge with one NaO8 hexagonal bipyramid, and edges with three BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Bi–O bond distances ranging from 2.14–2.17 Å. In the third Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra and edges with four equivalent BiO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 52°. All Bi–O bond lengths are 2.19 Å. In the fourth Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra, an edgeedge with one NaO8 hexagonal bipyramid, and edges with two equivalent BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Bi–O bond distances ranging from 2.15–2.17 Å. In the fifth Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Bi–O bond distances ranging from 2.15–2.17 Å. In the sixth Bi+3.90+ site, Bi+3.90+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra and edges with three BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–54°. There are four shorter (2.22 Å) and two longer (2.23 Å) Bi–O bond lengths. In the seventh Bi+3.90+ site, Bi+3.90+ is bonded to eight O2- atoms to form distorted BiO8 hexagonal bipyramids that share edges with four equivalent BiO8 hexagonal bipyramids and edges with six BiO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.35–2.68 Å. In the eighth Bi+3.90+ site, Bi+3.90+ is bonded to eight O2- atoms to form distorted BiO8 hexagonal bipyramids that share an edgeedge with one NaO8 hexagonal bipyramid, edges with two BiO8 hexagonal bipyramids, and edges with six BiO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.29–2.77 Å. In the ninth Bi+3.90+ site, Bi+3.90+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.36–2.70 Å. In the tenth Bi+3.90+ site, Bi+3.90+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.36–2.70 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Bi+3.90+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Bi+3.90+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Bi+3.90+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Bi+3.90+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Bi+3.90+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi+3.90+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to four Bi+3.90+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to four Bi+3.90+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Bi+3.90+ atoms. In the tenth O2- site, O2- is bonded to one Na1+ and three Bi+3.90+ atoms to form corner-sharing ONaBi3 tetrahedra. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to four Bi+3.90+ atoms. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi+3.90+ atoms.