Sr4Bi2O is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4mm space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one Bi(1), four equivalent Bi(2), and one O(1) atom. In the second Sr site, Sr(2) is bonded to one Bi(2), four equivalent Bi(1), and one O(1) atom to form a mixture of distorted edge and corner-sharing SrBi5O octahedra. The corner-sharing octahedral tilt angles are 18°. In the third Sr site, Sr(3) is bonded in a linear geometry to two equivalent Bi(1), two equivalent Bi(2), and two equivalent O(1) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to one Sr(1), four equivalent Sr(2), and four equivalent Sr(3) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to one Sr(2), four equivalent Sr(1), and four equivalent Sr(3) atoms. O(1) is bonded to one Sr(1), one Sr(2), and four equivalent Sr(3) atoms to form corner-sharing OSr6 octahedra. The corner-sharing octahedral tilt angles are 6°.
Sr4Bi2O is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4mm space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one Bi(1), four equivalent Bi(2), and one O(1) atom. The Sr(1)-Bi(1) bond length is 3.48 Å. All Sr(1)-Bi(2) bond lengths are 3.58 Å. The Sr(1)-O(1) bond length is 2.74 Å. In the second Sr site, Sr(2) is bonded to one Bi(2), four equivalent Bi(1), and one O(1) atom to form a mixture of distorted edge and corner-sharing SrBi5O octahedra. The corner-sharing octahedral tilt angles are 18°. The Sr(2)-Bi(2) bond length is 3.35 Å. All Sr(2)-Bi(1) bond lengths are 3.60 Å. The Sr(2)-O(1) bond length is 3.18 Å. In the third Sr site, Sr(3) is bonded in a linear geometry to two equivalent Bi(1), two equivalent Bi(2), and two equivalent O(1) atoms. Both Sr(3)-Bi(1) bond lengths are 3.52 Å. Both Sr(3)-Bi(2) bond lengths are 3.50 Å. Both Sr(3)-O(1) bond lengths are 2.52 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to one Sr(1), four equivalent Sr(2), and four equivalent Sr(3) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to one Sr(2), four equivalent Sr(1), and four equivalent Sr(3) atoms. O(1) is bonded to one Sr(1), one Sr(2), and four equivalent Sr(3) atoms to form corner-sharing OSr6 octahedra. The corner-sharing octahedral tilt angles are 6°.