TlSr2Br5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent Br(2), two equivalent Br(3), two equivalent Br(4), and two equivalent Br(5) atoms. In the second Sr site, Sr(2) is bonded to one Br(2), one Br(3), one Br(4), two equivalent Br(1), and two equivalent Br(5) atoms to form distorted edge-sharing SrBr7 pentagonal bipyramids. Tl(1) is bonded in a 1-coordinate geometry to two equivalent Br(1) atoms. There are five inequivalent Br sites. In the first Br site, Br(1) is bonded in a 4-coordinate geometry to two equivalent Sr(2) and two equivalent Tl(1) atoms. In the second Br site, Br(2) is bonded in a distorted T-shaped geometry to one Sr(2) and two equivalent Sr(1) atoms. In the third Br site, Br(3) is bonded in a 3-coordinate geometry to one Sr(2) and two equivalent Sr(1) atoms. In the fourth Br site, Br(4) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2) and two equivalent Sr(1) atoms. In the fifth Br site, Br(5) is bonded to two equivalent Sr(1) and two equivalent Sr(2) atoms to form a mixture of distorted corner and edge-sharing BrSr4 tetrahedra.
TlSr2Br5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent Br(2), two equivalent Br(3), two equivalent Br(4), and two equivalent Br(5) atoms. There is one shorter (3.19 Å) and one longer (3.30 Å) Sr(1)-Br(2) bond length. There is one shorter (3.15 Å) and one longer (3.23 Å) Sr(1)-Br(3) bond length. There is one shorter (3.17 Å) and one longer (3.19 Å) Sr(1)-Br(4) bond length. There is one shorter (3.22 Å) and one longer (3.23 Å) Sr(1)-Br(5) bond length. In the second Sr site, Sr(2) is bonded to one Br(2), one Br(3), one Br(4), two equivalent Br(1), and two equivalent Br(5) atoms to form distorted edge-sharing SrBr7 pentagonal bipyramids. The Sr(2)-Br(2) bond length is 3.12 Å. The Sr(2)-Br(3) bond length is 3.16 Å. The Sr(2)-Br(4) bond length is 3.23 Å. There is one shorter (3.03 Å) and one longer (3.10 Å) Sr(2)-Br(1) bond length. There is one shorter (3.09 Å) and one longer (3.10 Å) Sr(2)-Br(5) bond length. Tl(1) is bonded in a 1-coordinate geometry to two equivalent Br(1) atoms. There is one shorter (3.26 Å) and one longer (3.36 Å) Tl(1)-Br(1) bond length. There are five inequivalent Br sites. In the first Br site, Br(1) is bonded in a 4-coordinate geometry to two equivalent Sr(2) and two equivalent Tl(1) atoms. In the second Br site, Br(2) is bonded in a distorted T-shaped geometry to one Sr(2) and two equivalent Sr(1) atoms. In the third Br site, Br(3) is bonded in a 3-coordinate geometry to one Sr(2) and two equivalent Sr(1) atoms. In the fourth Br site, Br(4) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2) and two equivalent Sr(1) atoms. In the fifth Br site, Br(5) is bonded to two equivalent Sr(1) and two equivalent Sr(2) atoms to form a mixture of distorted corner and edge-sharing BrSr4 tetrahedra.