LaSrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. La(1) is bonded in a 8-coordinate geometry to one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(2) atoms. In the second O site, O(6) is bonded to two equivalent La(1) and two equivalent Al(1) atoms to form distorted OLa2Al2 tetrahedra that share corners with two equivalent O(4)Sr2LaAl tetrahedra, corners with two equivalent O(3)SrLa2Al tetrahedra, and edges with two equivalent O(3)SrLa2Al tetrahedra. In the third O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one La(1), one Al(1), and one Al(3) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Sr(1), one La(1), one Al(2), and one Al(3) atom. In the fifth O site, O(3) is bonded to one Sr(1), two equivalent La(1), and one Al(1) atom to form distorted OSrLa2Al tetrahedra that share  a cornercorner with one O(6)La2Al2 tetrahedra, corners with four equivalent O(4)Sr2LaAl tetrahedra,  an edgeedge with one O(6)La2Al2 tetrahedra, and  an edgeedge with one O(3)SrLa2Al tetrahedra. In the sixth O site, O(4) is bonded to two equivalent Sr(1), one La(1), and one Al(2) atom to form distorted OSr2LaAl tetrahedra that share  a cornercorner with one O(6)La2Al2 tetrahedra, corners with four equivalent O(3)SrLa2Al tetrahedra, and  an edgeedge with one O(4)Sr2LaAl tetrahedra.
LaSrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Sr(1)-O(3) bond length is 2.58 Å. The Sr(1)-O(5) bond length is 2.57 Å. Both Sr(1)-O(1) bond lengths are 2.59 Å. Both Sr(1)-O(2) bond lengths are 2.97 Å. Both Sr(1)-O(4) bond lengths are 2.70 Å. La(1) is bonded in a 8-coordinate geometry to one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The La(1)-O(4) bond length is 2.39 Å. The La(1)-O(6) bond length is 2.52 Å. Both La(1)-O(1) bond lengths are 2.93 Å. Both La(1)-O(2) bond lengths are 2.51 Å. Both La(1)-O(3) bond lengths are 2.59 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form corner-sharing AlO4 tetrahedra. The Al(1)-O(3) bond length is 1.75 Å. The Al(1)-O(6) bond length is 1.78 Å. Both Al(1)-O(1) bond lengths are 1.78 Å. In the second Al site, Al(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. The Al(2)-O(4) bond length is 1.75 Å. The Al(2)-O(5) bond length is 1.75 Å. Both Al(2)-O(2) bond lengths are 1.80 Å. In the third Al site, Al(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. Both Al(3)-O(1) bond lengths are 1.78 Å. Both Al(3)-O(2) bond lengths are 1.79 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(2) atoms. In the second O site, O(6) is bonded to two equivalent La(1) and two equivalent Al(1) atoms to form distorted OLa2Al2 tetrahedra that share corners with two equivalent O(4)Sr2LaAl tetrahedra, corners with two equivalent O(3)SrLa2Al tetrahedra, and edges with two equivalent O(3)SrLa2Al tetrahedra. In the third O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one La(1), one Al(1), and one Al(3) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Sr(1), one La(1), one Al(2), and one Al(3) atom. In the fifth O site, O(3) is bonded to one Sr(1), two equivalent La(1), and one Al(1) atom to form distorted OSrLa2Al tetrahedra that share  a cornercorner with one O(6)La2Al2 tetrahedra, corners with four equivalent O(4)Sr2LaAl tetrahedra,  an edgeedge with one O(6)La2Al2 tetrahedra, and  an edgeedge with one O(3)SrLa2Al tetrahedra. In the sixth O site, O(4) is bonded to two equivalent Sr(1), one La(1), and one Al(2) atom to form distorted OSr2LaAl tetrahedra that share  a cornercorner with one O(6)La2Al2 tetrahedra, corners with four equivalent O(3)SrLa2Al tetrahedra, and  an edgeedge with one O(4)Sr2LaAl tetrahedra.