Potassium barium bismuth oxide

KBa₄Bi₃O crystallizes in the centrosymmetric tetragonal space group I4/mcm. In this compound, bismuth is present as two anionic species, i.e. Bi₂^4? dumbbells Bi—Bi 3.113 (3) Å] and isolated Bi^3?. Atom Bi1 (Bi^3?) lies inside a bicapped square antiprism (2 × K and 8 × Ba). Atom Bi2, which forms the Bi₂^4? dumbbell, sits inside a bicapped distorted trigonal prism (2 × K and 6 × Ba). O atoms occupy tetra­hedral voids between Ba atoms.