Sr2Fe2GaAlO7 is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(7), and three equivalent O(6) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), and three equivalent O(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO5 square pyramids that share corners with four equivalent Fe(1)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with four equivalent Al(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(6), two equivalent O(1), and two equivalent O(7) atoms to form distorted FeO5 square pyramids that share corners with four equivalent Fe(2)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with four equivalent Al(1)O4 tetrahedra. Ga(1) is bonded to one O(3), one O(6), and two equivalent O(2) atoms to form GaO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid, and corners with two equivalent Ga(1)O4 tetrahedra. Al(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form AlO4 tetrahedra that share corners with four equivalent Fe(1)O5 square pyramids and corners with four equivalent Fe(2)O5 square pyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a 5-coordinate geometry to three equivalent Sr(1), one Fe(2), and one Ga(1) atom. In the second O site, O(7) is bonded to one Sr(1), two equivalent Fe(2), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, corners with two equivalent O(7)SrAlFe2 trigonal pyramids, corners with four equivalent O(1)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(1)SrAlFe2 trigonal pyramid. In the third O site, O(1) is bonded to one Sr(1), two equivalent Fe(2), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, corners with two equivalent O(1)SrAlFe2 trigonal pyramids, corners with four equivalent O(7)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(7)SrAlFe2 trigonal pyramid. In the fourth O site, O(2) is bonded to one Sr(1), one Sr(2), and two equivalent Ga(1) atoms to form distorted OSr2Ga2 tetrahedra that share  a cornercorner with one O(4)SrAlFe2 tetrahedra, corners with two equivalent O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, and  a cornercorner with one O(7)SrAlFe2 trigonal pyramid. In the fifth O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Sr(2), one Fe(1), and one Ga(1) atom. In the sixth O site, O(4) is bonded to one Sr(2), two equivalent Fe(1), and one Al(1) atom to form distorted OSrAlFe2 tetrahedra that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra, corners with two equivalent O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(7)SrAlFe2 trigonal pyramid, corners with four equivalent O(5)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(5)SrAlFe2 trigonal pyramid. In the seventh O site, O(5) is bonded to one Sr(2), two equivalent Fe(1), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra, corners with four equivalent O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(7)SrAlFe2 trigonal pyramid, corners with two equivalent O(5)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(4)SrAlFe2 tetrahedra.
Sr2Fe2GaAlO7 is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(7), and three equivalent O(6) atoms. The Sr(1)-O(1) bond length is 2.49 Å. The Sr(1)-O(2) bond length is 2.51 Å. The Sr(1)-O(7) bond length is 2.50 Å. There are a spread of Sr(1)-O(6) bond distances ranging from 2.49-2.93 Å. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), and three equivalent O(3) atoms. The Sr(2)-O(2) bond length is 2.50 Å. The Sr(2)-O(4) bond length is 2.53 Å. The Sr(2)-O(5) bond length is 2.53 Å. There are a spread of Sr(2)-O(3) bond distances ranging from 2.48-2.99 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO5 square pyramids that share corners with four equivalent Fe(1)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with four equivalent Al(1)O4 tetrahedra. The Fe(1)-O(3) bond length is 2.63 Å. There is one shorter (2.05 Å) and one longer (2.12 Å) Fe(1)-O(4) bond length. There is one shorter (2.07 Å) and one longer (2.15 Å) Fe(1)-O(5) bond length. In the second Fe site, Fe(2) is bonded to one O(6), two equivalent O(1), and two equivalent O(7) atoms to form distorted FeO5 square pyramids that share corners with four equivalent Fe(2)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with four equivalent Al(1)O4 tetrahedra. The Fe(2)-O(6) bond length is 2.32 Å. There is one shorter (2.01 Å) and one longer (2.29 Å) Fe(2)-O(1) bond length. There is one shorter (2.00 Å) and one longer (2.15 Å) Fe(2)-O(7) bond length. Ga(1) is bonded to one O(3), one O(6), and two equivalent O(2) atoms to form GaO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(2)O5 square pyramid, and corners with two equivalent Ga(1)O4 tetrahedra. The Ga(1)-O(3) bond length is 1.87 Å. The Ga(1)-O(6) bond length is 1.87 Å. There is one shorter (1.85 Å) and one longer (1.91 Å) Ga(1)-O(2) bond length. Al(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form AlO4 tetrahedra that share corners with four equivalent Fe(1)O5 square pyramids and corners with four equivalent Fe(2)O5 square pyramids. The Al(1)-O(1) bond length is 1.82 Å. The Al(1)-O(4) bond length is 1.85 Å. The Al(1)-O(5) bond length is 1.84 Å. The Al(1)-O(7) bond length is 1.82 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a 5-coordinate geometry to three equivalent Sr(1), one Fe(2), and one Ga(1) atom. In the second O site, O(7) is bonded to one Sr(1), two equivalent Fe(2), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, corners with two equivalent O(7)SrAlFe2 trigonal pyramids, corners with four equivalent O(1)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(1)SrAlFe2 trigonal pyramid. In the third O site, O(1) is bonded to one Sr(1), two equivalent Fe(2), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, corners with two equivalent O(1)SrAlFe2 trigonal pyramids, corners with four equivalent O(7)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(7)SrAlFe2 trigonal pyramid. In the fourth O site, O(2) is bonded to one Sr(1), one Sr(2), and two equivalent Ga(1) atoms to form distorted OSr2Ga2 tetrahedra that share  a cornercorner with one O(4)SrAlFe2 tetrahedra, corners with two equivalent O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(5)SrAlFe2 trigonal pyramid, and  a cornercorner with one O(7)SrAlFe2 trigonal pyramid. In the fifth O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Sr(2), one Fe(1), and one Ga(1) atom. In the sixth O site, O(4) is bonded to one Sr(2), two equivalent Fe(1), and one Al(1) atom to form distorted OSrAlFe2 tetrahedra that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra, corners with two equivalent O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(7)SrAlFe2 trigonal pyramid, corners with four equivalent O(5)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(5)SrAlFe2 trigonal pyramid. In the seventh O site, O(5) is bonded to one Sr(2), two equivalent Fe(1), and one Al(1) atom to form distorted OSrAlFe2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra, corners with four equivalent O(4)SrAlFe2 tetrahedra,  a cornercorner with one O(1)SrAlFe2 trigonal pyramid,  a cornercorner with one O(7)SrAlFe2 trigonal pyramid, corners with two equivalent O(5)SrAlFe2 trigonal pyramids, and  an edgeedge with one O(4)SrAlFe2 tetrahedra.