KSr(BiO3)2 crystallizes in the tetragonal I-42m space group. K(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted KO8 cuboctahedra that share corners with four equivalent K(1)O8 cuboctahedra and edges with eight equivalent Bi(1)O6 octahedra. Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form BiO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and edges with four equivalent K(1)O8 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-28°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(1), one Sr(1), and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded to two equivalent K(1), two equivalent Sr(1), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OK2Sr2Bi2 octahedra. The corner-sharing octahedra are not tilted.
KSr(BiO3)2 crystallizes in the tetragonal I-42m space group. K(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted KO8 cuboctahedra that share corners with four equivalent K(1)O8 cuboctahedra and edges with eight equivalent Bi(1)O6 octahedra. All K(1)-O(1) bond lengths are 2.83 Å. All K(1)-O(2) bond lengths are 3.00 Å. Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. All Sr(1)-O(1) bond lengths are 2.59 Å. All Sr(1)-O(2) bond lengths are 3.00 Å. Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form BiO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and edges with four equivalent K(1)O8 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-28°. Both Bi(1)-O(2) bond lengths are 2.18 Å. All Bi(1)-O(1) bond lengths are 2.18 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(1), one Sr(1), and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded to two equivalent K(1), two equivalent Sr(1), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OK2Sr2Bi2 octahedra. The corner-sharing octahedra are not tilted.