Sr4MgMn2(GaO5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and one O(9) atom. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. In the third Sr site, Sr(3) is bonded to one O(10), one O(3), one O(4), one O(5), and one O(7) atom to form distorted SrO5 square pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Ga(1)O4 tetrahedra, corners with two equivalent Ga(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 trigonal pyramid,  an edgeedge with one Mn(2)O5 square pyramid, and  an edgeedge with one Mn(1)O4 trigonal pyramid. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. Mg(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form MgO4 tetrahedra that share  a cornercorner with one Sr(3)O5 square pyramid, corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Ga(2)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 trigonal pyramid. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form distorted MnO4 trigonal pyramids that share  a cornercorner with one Sr(3)O5 square pyramid, corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra,  an edgeedge with one Sr(3)O5 square pyramid, and  an edgeedge with one Mg(1)O4 tetrahedra. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), one O(3), one O(7), and one O(8) atom to form distorted MnO5 square pyramids that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(1)O4 trigonal pyramids, and  an edgeedge with one Sr(3)O5 square pyramid. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid, corners with two equivalent Sr(3)O5 square pyramids,  a cornercorner with one Mn(1)O4 trigonal pyramid, and  an edgeedge with one Ga(2)O4 tetrahedra. In the second Ga site, Ga(2) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid, corners with two equivalent Sr(3)O5 square pyramids,  a cornercorner with one Mg(1)O4 tetrahedra, and  an edgeedge with one Ga(1)O4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(4), one Mg(1), one Mn(1), and one Mn(2) atom to form distorted OSr2MgMn2 trigonal bipyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(9)Sr2Ga2 trigonal pyramids, and corners with two equivalent O(8)Sr2MnGa trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), and one Mn(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Mn(1), and one Mn(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Mg(1), and one Mn(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Sr(3), one Mn(1), and one Ga(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Sr(2), one Sr(4), one Mg(1), and one Ga(2) atom. In the seventh O site, O(7) is bonded to one Sr(1), one Sr(3), one Mn(2), and one Ga(2) atom to form distorted OSr2MnGa tetrahedra that share corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids,  a cornercorner with one O(8)Sr2MnGa trigonal pyramid, corners with two equivalent O(10)Sr2Ga2 trigonal pyramids, and corners with two equivalent O(9)Sr2Ga2 trigonal pyramids. In the eighth O site, O(8) is bonded to one Sr(2), one Sr(4), one Mn(2), and one Ga(1) atom to form distorted OSr2MnGa trigonal pyramids that share  a cornercorner with one O(7)Sr2MnGa tetrahedra, corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids, corners with two equivalent O(10)Sr2Ga2 trigonal pyramids, and  an edgeedge with one O(9)Sr2Ga2 trigonal pyramid. In the ninth O site, O(9) is bonded to one Sr(1), one Sr(4), one Ga(1), and one Ga(2) atom to form OSr2Ga2 trigonal pyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids,  an edgeedge with one O(10)Sr2Ga2 trigonal pyramid, and  an edgeedge with one O(8)Sr2MnGa trigonal pyramid. In the tenth O site, O(10) is bonded to one Sr(2), one Sr(3), one Ga(1), and one Ga(2) atom to form distorted OSr2Ga2 trigonal pyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(8)Sr2MnGa trigonal pyramids, and  an edgeedge with one O(9)Sr2Ga2 trigonal pyramid.
Sr4MgMn2(GaO5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and one O(9) atom. The Sr(1)-O(1) bond length is 2.60 Å. The Sr(1)-O(3) bond length is 2.52 Å. The Sr(1)-O(5) bond length is 2.63 Å. The Sr(1)-O(7) bond length is 2.46 Å. The Sr(1)-O(9) bond length is 2.51 Å. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. The Sr(2)-O(10) bond length is 2.56 Å. The Sr(2)-O(2) bond length is 2.44 Å. The Sr(2)-O(3) bond length is 2.88 Å. The Sr(2)-O(4) bond length is 2.57 Å. The Sr(2)-O(6) bond length is 2.62 Å. The Sr(2)-O(8) bond length is 2.54 Å. In the third Sr site, Sr(3) is bonded to one O(10), one O(3), one O(4), one O(5), and one O(7) atom to form distorted SrO5 square pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Ga(1)O4 tetrahedra, corners with two equivalent Ga(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 trigonal pyramid,  an edgeedge with one Mn(2)O5 square pyramid, and  an edgeedge with one Mn(1)O4 trigonal pyramid. The Sr(3)-O(10) bond length is 2.54 Å. The Sr(3)-O(3) bond length is 2.55 Å. The Sr(3)-O(4) bond length is 2.55 Å. The Sr(3)-O(5) bond length is 2.46 Å. The Sr(3)-O(7) bond length is 2.45 Å. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. The Sr(4)-O(1) bond length is 2.60 Å. The Sr(4)-O(2) bond length is 2.58 Å. The Sr(4)-O(3) bond length is 3.19 Å. The Sr(4)-O(4) bond length is 2.86 Å. The Sr(4)-O(6) bond length is 2.56 Å. The Sr(4)-O(8) bond length is 2.64 Å. The Sr(4)-O(9) bond length is 2.52 Å. Mg(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form MgO4 tetrahedra that share  a cornercorner with one Sr(3)O5 square pyramid, corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Ga(2)O4 tetrahedra, and  an edgeedge with one Mn(1)O4 trigonal pyramid. The Mg(1)-O(1) bond length is 2.00 Å. The Mg(1)-O(2) bond length is 1.94 Å. The Mg(1)-O(4) bond length is 2.01 Å. The Mg(1)-O(6) bond length is 1.97 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form distorted MnO4 trigonal pyramids that share  a cornercorner with one Sr(3)O5 square pyramid, corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Ga(1)O4 tetrahedra,  an edgeedge with one Sr(3)O5 square pyramid, and  an edgeedge with one Mg(1)O4 tetrahedra. The Mn(1)-O(1) bond length is 2.12 Å. The Mn(1)-O(3) bond length is 1.99 Å. The Mn(1)-O(4) bond length is 2.12 Å. The Mn(1)-O(5) bond length is 2.02 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), one O(3), one O(7), and one O(8) atom to form distorted MnO5 square pyramids that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(1)O4 trigonal pyramids, and  an edgeedge with one Sr(3)O5 square pyramid. The Mn(2)-O(1) bond length is 2.19 Å. The Mn(2)-O(2) bond length is 2.12 Å. The Mn(2)-O(3) bond length is 2.22 Å. The Mn(2)-O(7) bond length is 2.50 Å. The Mn(2)-O(8) bond length is 2.19 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid, corners with two equivalent Sr(3)O5 square pyramids,  a cornercorner with one Mn(1)O4 trigonal pyramid, and  an edgeedge with one Ga(2)O4 tetrahedra. The Ga(1)-O(10) bond length is 1.92 Å. The Ga(1)-O(5) bond length is 1.83 Å. The Ga(1)-O(8) bond length is 1.82 Å. The Ga(1)-O(9) bond length is 1.99 Å. In the second Ga site, Ga(2) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid, corners with two equivalent Sr(3)O5 square pyramids,  a cornercorner with one Mg(1)O4 tetrahedra, and  an edgeedge with one Ga(1)O4 tetrahedra. The Ga(2)-O(10) bond length is 1.97 Å. The Ga(2)-O(6) bond length is 1.85 Å. The Ga(2)-O(7) bond length is 1.83 Å. The Ga(2)-O(9) bond length is 1.92 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(4), one Mg(1), one Mn(1), and one Mn(2) atom to form distorted OSr2MgMn2 trigonal bipyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(9)Sr2Ga2 trigonal pyramids, and corners with two equivalent O(8)Sr2MnGa trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), and one Mn(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Mn(1), and one Mn(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Mg(1), and one Mn(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Sr(3), one Mn(1), and one Ga(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Sr(2), one Sr(4), one Mg(1), and one Ga(2) atom. In the seventh O site, O(7) is bonded to one Sr(1), one Sr(3), one Mn(2), and one Ga(2) atom to form distorted OSr2MnGa tetrahedra that share corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids,  a cornercorner with one O(8)Sr2MnGa trigonal pyramid, corners with two equivalent O(10)Sr2Ga2 trigonal pyramids, and corners with two equivalent O(9)Sr2Ga2 trigonal pyramids. In the eighth O site, O(8) is bonded to one Sr(2), one Sr(4), one Mn(2), and one Ga(1) atom to form distorted OSr2MnGa trigonal pyramids that share  a cornercorner with one O(7)Sr2MnGa tetrahedra, corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids, corners with two equivalent O(10)Sr2Ga2 trigonal pyramids, and  an edgeedge with one O(9)Sr2Ga2 trigonal pyramid. In the ninth O site, O(9) is bonded to one Sr(1), one Sr(4), one Ga(1), and one Ga(2) atom to form OSr2Ga2 trigonal pyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(1)Sr2MgMn2 trigonal bipyramids,  an edgeedge with one O(10)Sr2Ga2 trigonal pyramid, and  an edgeedge with one O(8)Sr2MnGa trigonal pyramid. In the tenth O site, O(10) is bonded to one Sr(2), one Sr(3), one Ga(1), and one Ga(2) atom to form distorted OSr2Ga2 trigonal pyramids that share corners with two equivalent O(7)Sr2MnGa tetrahedra, corners with two equivalent O(8)Sr2MnGa trigonal pyramids, and  an edgeedge with one O(9)Sr2Ga2 trigonal pyramid.