Sr5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. In the second Sr site, Sr(2) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing SrBi5 square pyramids. In the third Sr site, Sr(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing SrBi5 square pyramids. In the fourth Sr site, Sr(4) is bonded in a 5-coordinate geometry to one Bi(1) and four equivalent Bi(2) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Sr(2), one Sr(3), one Sr(4), and four equivalent Sr(1) atoms to form distorted edge-sharing BiSr7 pentagonal bipyramids. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), two equivalent Sr(4), and three equivalent Sr(1) atoms.
Sr5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. There is one shorter (3.27 Å) and one longer (3.46 Å) Sr(1)-Bi(1) bond length. There are a spread of Sr(1)-Bi(2) bond distances ranging from 3.60-4.05 Å. In the second Sr site, Sr(2) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing SrBi5 square pyramids. The Sr(2)-Bi(1) bond length is 3.40 Å. There are two shorter (3.55 Å) and two longer (3.63 Å) Sr(2)-Bi(2) bond lengths. In the third Sr site, Sr(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form a mixture of distorted face, corner, and edge-sharing SrBi5 square pyramids. The Sr(3)-Bi(1) bond length is 3.48 Å. There are two shorter (3.52 Å) and two longer (3.54 Å) Sr(3)-Bi(2) bond lengths. In the fourth Sr site, Sr(4) is bonded in a 5-coordinate geometry to one Bi(1) and four equivalent Bi(2) atoms. The Sr(4)-Bi(1) bond length is 3.31 Å. There are two shorter (3.57 Å) and two longer (3.70 Å) Sr(4)-Bi(2) bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Sr(2), one Sr(3), one Sr(4), and four equivalent Sr(1) atoms to form distorted edge-sharing BiSr7 pentagonal bipyramids. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), two equivalent Sr(4), and three equivalent Sr(1) atoms.