Ba2MgCuHgO4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to one Mg(1), four equivalent O(1), and four equivalent O(2) atoms. Mg(1) is bonded to two equivalent Ba(1) and four equivalent Hg(1) atoms to form distorted MgBa2Hg4 octahedra that share corners with four equivalent Mg(1)Ba2Hg4 octahedra, corners with eight equivalent O(2)Ba4Cu2 octahedra, and edges with four equivalent Mg(1)Ba2Hg4 octahedra. The corner-sharing octahedral tilt angles range from 0-46°. Cu(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Hg(1) is bonded to four equivalent Mg(1) and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing HgMg4O2 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Hg(1) atom. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form OBa4Cu2 octahedra that share corners with two equivalent O(2)Ba4Cu2 octahedra, corners with four equivalent Mg(1)Ba2Hg4 octahedra, edges with two equivalent O(2)Ba4Cu2 octahedra, and faces with four equivalent O(2)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-46°.
Ba2MgCuHgO4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to one Mg(1), four equivalent O(1), and four equivalent O(2) atoms. The Ba(1)-Mg(1) bond length is 3.32 Å. All Ba(1)-O(1) bond lengths are 3.01 Å. All Ba(1)-O(2) bond lengths are 2.75 Å. Mg(1) is bonded to two equivalent Ba(1) and four equivalent Hg(1) atoms to form distorted MgBa2Hg4 octahedra that share corners with four equivalent Mg(1)Ba2Hg4 octahedra, corners with eight equivalent O(2)Ba4Cu2 octahedra, and edges with four equivalent Mg(1)Ba2Hg4 octahedra. The corner-sharing octahedral tilt angles range from 0-46°. All Mg(1)-Hg(1) bond lengths are 2.79 Å. Cu(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Cu(1)-O(2) bond lengths are 1.98 Å. Hg(1) is bonded to four equivalent Mg(1) and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing HgMg4O2 octahedra. The corner-sharing octahedra are not tilted. Both Hg(1)-O(1) bond lengths are 2.20 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Hg(1) atom. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form OBa4Cu2 octahedra that share corners with two equivalent O(2)Ba4Cu2 octahedra, corners with four equivalent Mg(1)Ba2Hg4 octahedra, edges with two equivalent O(2)Ba4Cu2 octahedra, and faces with four equivalent O(2)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-46°.