Sr4MgFe4O11 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), 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 5-coordinate geometry to one O(1), one O(11), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(2), one O(8), and one O(9) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(7), and one O(8) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form corner-sharing FeO5 square pyramids. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing FeO5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Mg(1), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom to form distorted corner-sharing OSr3Fe tetrahedra. In the fourth O site, O(4) is bonded to one Sr(2), one Sr(3), one Sr(4), one Fe(2), and one Fe(3) atom to form distorted corner-sharing OSr3Fe2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Fe(2), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(3), one Mg(1), one Fe(2), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(4), one Mg(1), one Fe(3), and one Fe(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), one Fe(1), and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), one Fe(1), and one Fe(2) atom.
Sr4MgFe4O11 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(5), one O(7), and one O(9) atom. The Sr(1)-O(1) bond length is 2.87 Å. The Sr(1)-O(10) bond length is 2.65 Å. The Sr(1)-O(2) bond length is 2.62 Å. The Sr(1)-O(3) bond length is 2.55 Å. The Sr(1)-O(5) bond length is 2.57 Å. The Sr(1)-O(7) bond length is 2.74 Å. The Sr(1)-O(9) bond length is 2.84 Å. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Sr(2)-O(1) bond length is 2.50 Å. The Sr(2)-O(11) bond length is 2.37 Å. The Sr(2)-O(3) bond length is 2.70 Å. The Sr(2)-O(4) bond length is 2.40 Å. The Sr(2)-O(5) bond length is 2.96 Å. The Sr(2)-O(6) bond length is 2.85 Å. The Sr(2)-O(7) bond length is 2.52 Å. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Sr(3)-O(1) bond length is 2.64 Å. The Sr(3)-O(10) bond length is 3.05 Å. The Sr(3)-O(2) bond length is 2.96 Å. The Sr(3)-O(3) bond length is 2.59 Å. The Sr(3)-O(4) bond length is 2.67 Å. The Sr(3)-O(5) bond length is 3.07 Å. The Sr(3)-O(6) bond length is 2.62 Å. The Sr(3)-O(7) bond length is 3.19 Å. The Sr(3)-O(8) bond length is 2.56 Å. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. The Sr(4)-O(10) bond length is 2.49 Å. The Sr(4)-O(11) bond length is 2.83 Å. The Sr(4)-O(4) bond length is 2.54 Å. The Sr(4)-O(5) bond length is 2.76 Å. The Sr(4)-O(6) bond length is 2.47 Å. The Sr(4)-O(9) bond length is 2.51 Å. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(2), one O(8), and one O(9) atom. The Mg(1)-O(11) bond length is 1.90 Å. The Mg(1)-O(2) bond length is 1.98 Å. The Mg(1)-O(8) bond length is 2.01 Å. The Mg(1)-O(9) bond length is 2.01 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form distorted corner-sharing FeO5 trigonal bipyramids. The Fe(1)-O(10) bond length is 1.97 Å. The Fe(1)-O(11) bond length is 2.04 Å. The Fe(1)-O(2) bond length is 2.20 Å. The Fe(1)-O(5) bond length is 1.95 Å. The Fe(1)-O(6) bond length is 1.94 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(7), and one O(8) atom to form distorted corner-sharing FeO5 trigonal bipyramids. The Fe(2)-O(10) bond length is 1.94 Å. The Fe(2)-O(11) bond length is 2.18 Å. The Fe(2)-O(4) bond length is 2.11 Å. The Fe(2)-O(7) bond length is 1.98 Å. The Fe(2)-O(8) bond length is 1.97 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form corner-sharing FeO5 square pyramids. The Fe(3)-O(2) bond length is 1.99 Å. The Fe(3)-O(4) bond length is 2.03 Å. The Fe(3)-O(5) bond length is 2.12 Å. The Fe(3)-O(7) bond length is 2.02 Å. The Fe(3)-O(9) bond length is 1.95 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing FeO5 trigonal bipyramids. The Fe(4)-O(1) bond length is 1.89 Å. The Fe(4)-O(3) bond length is 1.91 Å. The Fe(4)-O(6) bond length is 2.08 Å. The Fe(4)-O(8) bond length is 2.10 Å. The Fe(4)-O(9) bond length is 2.04 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Mg(1), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom to form distorted corner-sharing OSr3Fe tetrahedra. In the fourth O site, O(4) is bonded to one Sr(2), one Sr(3), one Sr(4), one Fe(2), and one Fe(3) atom to form distorted corner-sharing OSr3Fe2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Fe(2), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(3), one Mg(1), one Fe(2), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(4), one Mg(1), one Fe(3), and one Fe(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), one Fe(1), and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), one Fe(1), and one Fe(2) atom.