Sr2YW2GaO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. Y(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(4) atoms. W(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(4) atoms to form WO5 square pyramids that share corners with four equivalent W(1)O5 square pyramids and  a cornercorner with one Ga(1)O4 tetrahedra. Ga(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form GaO4 tetrahedra that share corners with two equivalent W(1)O5 square pyramids and corners with two equivalent Ga(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Y(1), and two equivalent W(1) atoms. In the second O site, O(2) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form OSr2Ga2 tetrahedra that share corners with two equivalent O(2)Sr2Ga2 tetrahedra and corners with two equivalent O(4)SrYW2 trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one W(1), and one Ga(1) atom. In the fourth O site, O(4) is bonded to one Sr(1), one Y(1), and two equivalent W(1) atoms to form distorted OSrYW2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra and corners with three equivalent O(4)SrYW2 trigonal pyramids.
Sr2YW2GaO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. The Sr(1)-O(1) bond length is 2.46 Å. The Sr(1)-O(2) bond length is 2.53 Å. The Sr(1)-O(4) bond length is 2.47 Å. There is one shorter (2.52 Å) and one longer (2.63 Å) Sr(1)-O(3) bond length. Y(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Y(1)-O(1) bond lengths are 2.28 Å. Both Y(1)-O(4) bond lengths are 2.27 Å. W(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(4) atoms to form WO5 square pyramids that share corners with four equivalent W(1)O5 square pyramids and  a cornercorner with one Ga(1)O4 tetrahedra. The W(1)-O(3) bond length is 2.43 Å. There is one shorter (2.17 Å) and one longer (2.18 Å) W(1)-O(1) bond length. Both W(1)-O(4) bond lengths are 2.17 Å. Ga(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form GaO4 tetrahedra that share corners with two equivalent W(1)O5 square pyramids and corners with two equivalent Ga(1)O4 tetrahedra. Both Ga(1)-O(2) bond lengths are 1.93 Å. Both Ga(1)-O(3) bond lengths are 1.85 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Y(1), and two equivalent W(1) atoms. In the second O site, O(2) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form OSr2Ga2 tetrahedra that share corners with two equivalent O(2)Sr2Ga2 tetrahedra and corners with two equivalent O(4)SrYW2 trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one W(1), and one Ga(1) atom. In the fourth O site, O(4) is bonded to one Sr(1), one Y(1), and two equivalent W(1) atoms to form distorted OSrYW2 trigonal pyramids that share  a cornercorner with one O(2)Sr2Ga2 tetrahedra and corners with three equivalent O(4)SrYW2 trigonal pyramids.