Materials Data on K2BiBr5O2 by Materials Project
KOBrKBiOBr(Br)3 crystallizes in the orthorhombic Pnma space group. The structure is one-dimensional and consists of twenty-four hydrobromic acid molecules; four KOBr clusters; and four KBiOBr ribbons oriented in the (1, 0, 0) direction. In each KOBr cluster, there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in an L-shaped geometry to two equivalent O2- atoms. Both K–O bond lengths are 2.60 Å. In the second K1+ site, K1+ is bonded in an L-shaped geometry to two equivalent O2- atoms. Both K–O bond lengths are 2.71 Å. O2- is bonded in a distorted trigonal planar geometry to two K1+ and one Br+0.20+ atom. The O–Br bond length is 1.78 Å. Br+0.20+ is bonded in a single-bond geometry to one O2- atom. In each KBiOBr ribbon, K1+ is bonded in a distorted bent 120 degrees geometry to two equivalent O2- atoms. There are one shorter (2.77 Å) and one longer (3.32 Å) K–O bond lengths. Bi1+ is bonded in a single-bond geometry to one O2- atom. The Bi–O bond length is 2.28 Å. O2- is bonded in a 3-coordinate geometry to two equivalent K1+, one Bi1+, and one Br+0.20+ atom. The O–Br bond length is 1.88 Å. Br+0.20+ is bonded in a single-bond geometry to one O2- atom.