Sr2MgCuO4 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. Mg(1) is bonded in a linear geometry to two equivalent O(2) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Sr(1) and one Mg(1) atom.
Sr2MgCuO4 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. There is one shorter (2.47 Å) and two longer (2.96 Å) Sr(1)-O(2) bond lengths. There are two shorter (2.53 Å) and two longer (2.62 Å) Sr(1)-O(1) bond lengths. Mg(1) is bonded in a linear geometry to two equivalent O(2) atoms. Both Mg(1)-O(2) bond lengths are 1.86 Å. Cu(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All Cu(1)-O(1) bond lengths are 1.91 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Sr(1) and one Mg(1) atom.