SrPrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(4), and two equivalent O(5) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), two equivalent Pr(1), and one Al(1) atom to form distorted OSrPr2Al tetrahedra that share  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(2)Sr2PrAl tetrahedra,  an edgeedge with one O(4)Pr2Al2 tetrahedra, and  an edgeedge with one O(1)SrPr2Al tetrahedra. In the second O site, O(2) is bonded to two equivalent Sr(1), one Pr(1), and one Al(2) atom to form distorted OSr2PrAl tetrahedra that share  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(1)SrPr2Al tetrahedra, and  an edgeedge with one O(2)Sr2PrAl tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Pr(1) and two equivalent Al(1) atoms to form distorted OPr2Al2 tetrahedra that share corners with two equivalent O(2)Sr2PrAl tetrahedra, corners with two equivalent O(1)SrPr2Al tetrahedra, and edges with two equivalent O(1)SrPr2Al tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Sr(1), one Pr(1), one Al(1), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Pr(1), one Al(2), and one Al(3) atom.
SrPrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. The Sr(1)-O(1) bond length is 2.59 Å. The Sr(1)-O(3) bond length is 2.56 Å. Both Sr(1)-O(2) bond lengths are 2.69 Å. Both Sr(1)-O(5) bond lengths are 2.59 Å. Both Sr(1)-O(6) bond lengths are 2.96 Å. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. The Pr(1)-O(2) bond length is 2.38 Å. The Pr(1)-O(4) bond length is 2.48 Å. Both Pr(1)-O(1) bond lengths are 2.56 Å. Both Pr(1)-O(5) bond lengths are 2.91 Å. Both Pr(1)-O(6) bond lengths are 2.49 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(4), and two equivalent O(5) atoms to form corner-sharing AlO4 tetrahedra. The Al(1)-O(1) bond length is 1.75 Å. The Al(1)-O(4) bond length is 1.78 Å. Both Al(1)-O(5) bond lengths are 1.78 Å. In the second Al site, Al(2) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. The Al(2)-O(2) bond length is 1.74 Å. The Al(2)-O(3) bond length is 1.75 Å. Both Al(2)-O(6) bond lengths are 1.80 Å. In the third Al site, Al(3) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. Both Al(3)-O(5) bond lengths are 1.77 Å. Both Al(3)-O(6) bond lengths are 1.79 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), two equivalent Pr(1), and one Al(1) atom to form distorted OSrPr2Al tetrahedra that share  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(2)Sr2PrAl tetrahedra,  an edgeedge with one O(4)Pr2Al2 tetrahedra, and  an edgeedge with one O(1)SrPr2Al tetrahedra. In the second O site, O(2) is bonded to two equivalent Sr(1), one Pr(1), and one Al(2) atom to form distorted OSr2PrAl tetrahedra that share  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(1)SrPr2Al tetrahedra, and  an edgeedge with one O(2)Sr2PrAl tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Pr(1) and two equivalent Al(1) atoms to form distorted OPr2Al2 tetrahedra that share corners with two equivalent O(2)Sr2PrAl tetrahedra, corners with two equivalent O(1)SrPr2Al tetrahedra, and edges with two equivalent O(1)SrPr2Al tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Sr(1), one Pr(1), one Al(1), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Pr(1), one Al(2), and one Al(3) atom.