Sr28In11 crystallizes in the orthorhombic Imm2 space group. There are fifteen inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one In(5) and two equivalent In(4) atoms. In the second Sr site, Sr(2) is bonded in a trigonal planar geometry to three equivalent In(3) atoms. In the third Sr site, Sr(3) is bonded to one In(5) and three equivalent In(3) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. In the fourth Sr site, Sr(4) is bonded to one In(1), one In(5), and two equivalent In(4) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. In the fifth Sr site, Sr(5) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(1) atoms. In the sixth Sr site, Sr(6) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(5) atoms. In the seventh Sr site, Sr(7) is bonded in a distorted trigonal planar geometry to one In(3) and two equivalent In(5) atoms. In the eighth Sr site, Sr(8) is bonded to one In(1), one In(2), and two equivalent In(6) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. In the ninth Sr site, Sr(9) is bonded in a distorted trigonal non-coplanar geometry to one In(6) and two equivalent In(1) atoms. In the tenth Sr site, Sr(10) is bonded to one In(3), one In(4), and two equivalent In(5) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. In the eleventh Sr site, Sr(11) is bonded in a trigonal planar geometry to one In(1) and two equivalent In(6) atoms. In the twelfth Sr site, Sr(12) is bonded in a distorted trigonal planar geometry to one In(1) and two equivalent In(4) atoms. In the thirteenth Sr site, Sr(13) is bonded to two equivalent In(2) and two equivalent In(6) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. In the fourteenth Sr site, Sr(14) is bonded in a single-bond geometry to one In(2) atom. In the fifteenth Sr site, Sr(15) is bonded in a distorted trigonal non-coplanar geometry to one In(6) and two equivalent In(2) atoms. There are six inequivalent In sites. In the first In site, In(1) is bonded in a body-centered cubic geometry to one Sr(11), one Sr(12), one Sr(4), one Sr(8), two equivalent Sr(5), and two equivalent Sr(9) atoms. In the second In site, In(2) is bonded in a 9-coordinate geometry to one Sr(14), two equivalent Sr(13), two equivalent Sr(8), and four equivalent Sr(15) atoms. In the third In site, In(3) is bonded in a 8-coordinate geometry to one Sr(10), one Sr(7), three equivalent Sr(2), and three equivalent Sr(3) atoms. In the fourth In site, In(4) is bonded in a 9-coordinate geometry to one Sr(10), one Sr(5), one Sr(6), two equivalent Sr(1), two equivalent Sr(12), and two equivalent Sr(4) atoms. In the fifth In site, In(5) is bonded in a 9-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), two equivalent Sr(10), two equivalent Sr(6), and two equivalent Sr(7) atoms. In the sixth In site, In(6) is bonded in a 7-coordinate geometry to one Sr(13), one Sr(15), one Sr(9), two equivalent Sr(11), and two equivalent Sr(8) atoms.
Sr28In11 crystallizes in the orthorhombic Imm2 space group. There are fifteen inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one In(5) and two equivalent In(4) atoms. The Sr(1)-In(5) bond length is 3.37 Å. Both Sr(1)-In(4) bond lengths are 3.93 Å. In the second Sr site, Sr(2) is bonded in a trigonal planar geometry to three equivalent In(3) atoms. There is one shorter (3.42 Å) and two longer (3.45 Å) Sr(2)-In(3) bond lengths. In the third Sr site, Sr(3) is bonded to one In(5) and three equivalent In(3) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. The Sr(3)-In(5) bond length is 3.44 Å. There are two shorter (3.63 Å) and one longer (3.84 Å) Sr(3)-In(3) bond length. In the fourth Sr site, Sr(4) is bonded to one In(1), one In(5), and two equivalent In(4) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. The Sr(4)-In(1) bond length is 3.50 Å. The Sr(4)-In(5) bond length is 3.38 Å. Both Sr(4)-In(4) bond lengths are 3.69 Å. In the fifth Sr site, Sr(5) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(1) atoms. The Sr(5)-In(4) bond length is 3.44 Å. Both Sr(5)-In(1) bond lengths are 3.58 Å. In the sixth Sr site, Sr(6) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(5) atoms. The Sr(6)-In(4) bond length is 3.37 Å. Both Sr(6)-In(5) bond lengths are 3.78 Å. In the seventh Sr site, Sr(7) is bonded in a distorted trigonal planar geometry to one In(3) and two equivalent In(5) atoms. The Sr(7)-In(3) bond length is 3.44 Å. Both Sr(7)-In(5) bond lengths are 3.61 Å. In the eighth Sr site, Sr(8) is bonded to one In(1), one In(2), and two equivalent In(6) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. The Sr(8)-In(1) bond length is 3.63 Å. The Sr(8)-In(2) bond length is 3.42 Å. Both Sr(8)-In(6) bond lengths are 3.66 Å. In the ninth Sr site, Sr(9) is bonded in a distorted trigonal non-coplanar geometry to one In(6) and two equivalent In(1) atoms. The Sr(9)-In(6) bond length is 3.42 Å. Both Sr(9)-In(1) bond lengths are 3.50 Å. In the tenth Sr site, Sr(10) is bonded to one In(3), one In(4), and two equivalent In(5) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. The Sr(10)-In(3) bond length is 3.40 Å. The Sr(10)-In(4) bond length is 3.35 Å. Both Sr(10)-In(5) bond lengths are 3.70 Å. In the eleventh Sr site, Sr(11) is bonded in a trigonal planar geometry to one In(1) and two equivalent In(6) atoms. The Sr(11)-In(1) bond length is 3.45 Å. Both Sr(11)-In(6) bond lengths are 3.47 Å. In the twelfth Sr site, Sr(12) is bonded in a distorted trigonal planar geometry to one In(1) and two equivalent In(4) atoms. The Sr(12)-In(1) bond length is 3.48 Å. Both Sr(12)-In(4) bond lengths are 3.54 Å. In the thirteenth Sr site, Sr(13) is bonded to two equivalent In(2) and two equivalent In(6) atoms to form a mixture of distorted corner and edge-sharing SrIn4 tetrahedra. Both Sr(13)-In(2) bond lengths are 3.70 Å. Both Sr(13)-In(6) bond lengths are 3.34 Å. In the fourteenth Sr site, Sr(14) is bonded in a single-bond geometry to one In(2) atom. The Sr(14)-In(2) bond length is 3.36 Å. In the fifteenth Sr site, Sr(15) is bonded in a distorted trigonal non-coplanar geometry to one In(6) and two equivalent In(2) atoms. The Sr(15)-In(6) bond length is 3.39 Å. Both Sr(15)-In(2) bond lengths are 3.69 Å. There are six inequivalent In sites. In the first In site, In(1) is bonded in a body-centered cubic geometry to one Sr(11), one Sr(12), one Sr(4), one Sr(8), two equivalent Sr(5), and two equivalent Sr(9) atoms. In the second In site, In(2) is bonded in a 9-coordinate geometry to one Sr(14), two equivalent Sr(13), two equivalent Sr(8), and four equivalent Sr(15) atoms. In the third In site, In(3) is bonded in a 8-coordinate geometry to one Sr(10), one Sr(7), three equivalent Sr(2), and three equivalent Sr(3) atoms. In the fourth In site, In(4) is bonded in a 9-coordinate geometry to one Sr(10), one Sr(5), one Sr(6), two equivalent Sr(1), two equivalent Sr(12), and two equivalent Sr(4) atoms. In the fifth In site, In(5) is bonded in a 9-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), two equivalent Sr(10), two equivalent Sr(6), and two equivalent Sr(7) atoms. In the sixth In site, In(6) is bonded in a 7-coordinate geometry to one Sr(13), one Sr(15), one Sr(9), two equivalent Sr(11), and two equivalent Sr(8) atoms.