MgFe2(SbO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(7) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent Sb(2)O5 trigonal bipyramids and edges with two equivalent Sb(1)O6 octahedra. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), one O(7), and one O(8) atom. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with three equivalent Sb(2)O5 trigonal bipyramids and edges with two equivalent Fe(1)O6 octahedra. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(6), one O(7), and one O(8) atom to form distorted SbO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Sb(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom.
MgFe2(SbO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(7) atom. The Mg(1)-O(1) bond length is 2.04 Å. The Mg(1)-O(3) bond length is 1.93 Å. The Mg(1)-O(4) bond length is 1.98 Å. The Mg(1)-O(7) bond length is 2.06 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent Sb(2)O5 trigonal bipyramids and edges with two equivalent Sb(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.12 Å. The Fe(1)-O(3) bond length is 2.09 Å. The Fe(1)-O(4) bond length is 2.03 Å. The Fe(1)-O(5) bond length is 2.17 Å. The Fe(1)-O(6) bond length is 2.52 Å. The Fe(1)-O(7) bond length is 2.12 Å. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), one O(7), and one O(8) atom. The Fe(2)-O(1) bond length is 2.26 Å. The Fe(2)-O(2) bond length is 2.16 Å. The Fe(2)-O(5) bond length is 1.94 Å. The Fe(2)-O(7) bond length is 2.25 Å. The Fe(2)-O(8) bond length is 2.16 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with three equivalent Sb(2)O5 trigonal bipyramids and edges with two equivalent Fe(1)O6 octahedra. The Sb(1)-O(2) bond length is 2.12 Å. The Sb(1)-O(3) bond length is 1.98 Å. The Sb(1)-O(4) bond length is 1.98 Å. The Sb(1)-O(5) bond length is 1.94 Å. The Sb(1)-O(6) bond length is 2.07 Å. The Sb(1)-O(8) bond length is 2.12 Å. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(6), one O(7), and one O(8) atom to form distorted SbO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. The Sb(2)-O(1) bond length is 2.02 Å. The Sb(2)-O(2) bond length is 2.01 Å. The Sb(2)-O(6) bond length is 1.97 Å. The Sb(2)-O(7) bond length is 2.02 Å. The Sb(2)-O(8) bond length is 2.00 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Sb(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom.