La4Sr3O9 crystallizes in the trigonal R3 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(3) atoms. In the third Sr site, Sr(3) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. There are four inequivalent La sites. In the first La site, La(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form corner-sharing LaO6 octahedra. The corner-sharing octahedral tilt angles are 36°. In the second La site, La(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. In the third La site, La(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form corner-sharing LaO6 octahedra. The corner-sharing octahedral tilt angles are 36°. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(2), one Sr(3), one La(1), and one La(3) atom to form a mixture of distorted corner and edge-sharing OSr3La2 trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one La(2), one La(3), and one La(4) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Sr(2), one La(1), one La(2), and one La(4) atom.
La4Sr3O9 crystallizes in the trigonal R3 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Sr(1)-O(1) bond lengths are 2.83 Å. All Sr(1)-O(2) bond lengths are 2.51 Å. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(3) atoms. All Sr(2)-O(1) bond lengths are 2.86 Å. All Sr(2)-O(3) bond lengths are 2.49 Å. In the third Sr site, Sr(3) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Sr(3)-O(1) bond lengths are 2.44 Å. All Sr(3)-O(2) bond lengths are 3.06 Å. There are four inequivalent La sites. In the first La site, La(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form corner-sharing LaO6 octahedra. The corner-sharing octahedral tilt angles are 36°. All La(1)-O(1) bond lengths are 2.37 Å. All La(1)-O(3) bond lengths are 2.51 Å. In the second La site, La(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. All La(2)-O(2) bond lengths are 2.34 Å. All La(2)-O(3) bond lengths are 2.60 Å. In the third La site, La(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form corner-sharing LaO6 octahedra. The corner-sharing octahedral tilt angles are 36°. All La(3)-O(1) bond lengths are 2.40 Å. All La(3)-O(2) bond lengths are 2.42 Å. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. All La(4)-O(2) bond lengths are 2.81 Å. All La(4)-O(3) bond lengths are 2.31 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(2), one Sr(3), one La(1), and one La(3) atom to form a mixture of distorted corner and edge-sharing OSr3La2 trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one La(2), one La(3), and one La(4) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Sr(2), one La(1), one La(2), and one La(4) atom.