DOI: 10.17188/1204002
title: Materials Data on K4Bi2O5 by Materials Project

description: K4Bi2O5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to five O2- atoms to form distorted KO5 trigonal bipyramids that share a cornercorner with one KO6 octahedra, corners with two equivalent KO5 trigonal bipyramids, edges with five KO6 octahedra, and an edgeedge with one KO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 24°. There are a spread of K–O bond distances ranging from 2.73–3.00 Å. In the second K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two equivalent KO6 octahedra, a cornercorner with one KO5 trigonal bipyramid, edges with five KO6 octahedra, and an edgeedge with one KO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 13°. There are a spread of K–O bond distances ranging from 2.74–2.98 Å. In the third K1+ site, K1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 2.68–2.73 Å. In the fourth K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two equivalent KO6 octahedra, edges with four KO6 octahedra, and edges with four equivalent KO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. There are a spread of K–O bond distances ranging from 2.70–3.12 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.08–2.16 Å. In the second Bi3+ site, Bi3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.08–2.46 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four K1+ and one Bi3+ atom to form distorted OK4Bi trigonal bipyramids that share corners with three OK4Bi2 octahedra, a cornercorner with one OK3Bi2 trigonal bipyramid, edges with three OK5Bi octahedra, and edges with two OK4Bi trigonal bipyramids. The corner-sharing octahedra tilt angles range from 18–81°. In the second O2- site, O2- is bonded to five K1+ and one Bi3+ atom to form distorted OK5Bi octahedra that share corners with two equivalent OK5Bi octahedra, corners with three OK3Bi2 trigonal bipyramids, edges with four OK5Bi octahedra, and edges with two OK4Bi trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one Bi3+ atom. In the fourth O2- site, O2- is bonded to three K1+ and two equivalent Bi3+ atoms to form distorted OK3Bi2 trigonal bipyramids that share corners with four OK4Bi2 octahedra, a cornercorner with one OK4Bi trigonal bipyramid, edges with two OK5Bi octahedra, and edges with two OK4Bi trigonal bipyramids. The corner-sharing octahedra tilt angles range from 13–79°. In the fifth O2- site, O2- is bonded to four K1+ and two Bi3+ atoms to form distorted OK4Bi2 octahedra that share corners with two equivalent OK4Bi2 octahedra, corners with four OK3Bi2 trigonal bipyramids, edges with five OK5Bi octahedra, and edges with three OK4Bi trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°.