MgCu2(O3I)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a trigonal bipyramidal geometry to one O(1), one O(2), one O(4), one O(5), and one O(9) atom. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square pyramidal geometry to one O(10), one O(12), one O(3), one O(6), and one O(7) atom. In the second Cu site, Cu(2) is bonded in a distorted see-saw-like geometry to one O(11), one O(5), one O(8), and one O(9) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Mg(1) and one I(4) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one I(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(4) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one I(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Cu(2), and one I(4) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(3) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one I(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Cu(2) and one I(1) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Cu(2), and one I(2) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(1) atom. In the eleventh O site, O(11) is bonded in a water-like geometry to one Cu(2) and one I(2) atom. In the twelfth O site, O(12) is bonded in a water-like geometry to one Cu(1) and one I(1) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(12), and one O(8) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to one O(11), one O(7), and one O(9) atom. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(4), and one O(6) atom. In the fourth I site, I(4) is bonded in a distorted T-shaped geometry to one O(1), one O(3), and one O(5) atom.
MgCu2(O3I)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a trigonal bipyramidal geometry to one O(1), one O(2), one O(4), one O(5), and one O(9) atom. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(2) bond length is 2.03 Å. The Mg(1)-O(4) bond length is 2.02 Å. The Mg(1)-O(5) bond length is 2.26 Å. The Mg(1)-O(9) bond length is 2.03 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square pyramidal geometry to one O(10), one O(12), one O(3), one O(6), and one O(7) atom. The Cu(1)-O(10) bond length is 2.07 Å. The Cu(1)-O(12) bond length is 2.23 Å. The Cu(1)-O(3) bond length is 2.01 Å. The Cu(1)-O(6) bond length is 2.12 Å. The Cu(1)-O(7) bond length is 2.09 Å. In the second Cu site, Cu(2) is bonded in a distorted see-saw-like geometry to one O(11), one O(5), one O(8), and one O(9) atom. The Cu(2)-O(11) bond length is 2.10 Å. The Cu(2)-O(5) bond length is 1.98 Å. The Cu(2)-O(8) bond length is 2.13 Å. The Cu(2)-O(9) bond length is 2.01 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Mg(1) and one I(4) atom. The O(1)-I(4) bond length is 1.84 Å. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one I(3) atom. The O(2)-I(3) bond length is 1.84 Å. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(4) atom. The O(3)-I(4) bond length is 1.84 Å. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one I(3) atom. The O(4)-I(3) bond length is 1.86 Å. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Cu(2), and one I(4) atom. The O(5)-I(4) bond length is 1.93 Å. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(3) atom. The O(6)-I(3) bond length is 1.84 Å. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one I(2) atom. The O(7)-I(2) bond length is 1.84 Å. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Cu(2) and one I(1) atom. The O(8)-I(1) bond length is 1.86 Å. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Cu(2), and one I(2) atom. The O(9)-I(2) bond length is 1.91 Å. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(1) and one I(1) atom. The O(10)-I(1) bond length is 1.83 Å. In the eleventh O site, O(11) is bonded in a water-like geometry to one Cu(2) and one I(2) atom. The O(11)-I(2) bond length is 1.85 Å. In the twelfth O site, O(12) is bonded in a water-like geometry to one Cu(1) and one I(1) atom. The O(12)-I(1) bond length is 1.84 Å. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(12), and one O(8) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to one O(11), one O(7), and one O(9) atom. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(4), and one O(6) atom. In the fourth I site, I(4) is bonded in a distorted T-shaped geometry to one O(1), one O(3), and one O(5) atom.