Ba2MgTm(CuO2)4 crystallizes in the monoclinic P2/m space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. Tm(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(4) and three equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1) and three equivalent Cu(2) atoms. In the second O site, O(2) is bonded to two equivalent Ba(1), two equivalent Tm(1), and two equivalent Cu(1) atoms to form a mixture of distorted edge and corner-sharing OBa2Tm2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Tm(1), and two equivalent Cu(1) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Ba(1), one Cu(1), and one Cu(2) atom.
Ba2MgTm(CuO2)4 crystallizes in the monoclinic P2/m space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Both Ba(1)-O(2) bond lengths are 2.93 Å. Both Ba(1)-O(3) bond lengths are 3.03 Å. There are two shorter (2.77 Å) and two longer (2.79 Å) Ba(1)-O(4) bond lengths. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. All Mg(1)-O(1) bond lengths are 2.23 Å. Tm(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. All Tm(1)-O(2) bond lengths are 2.36 Å. There are two shorter (2.41 Å) and two longer (2.43 Å) Tm(1)-O(3) bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. The Cu(1)-O(4) bond length is 2.68 Å. Both Cu(1)-O(2) bond lengths are 1.98 Å. Both Cu(1)-O(3) bond lengths are 1.88 Å. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(4) and three equivalent O(1) atoms. The Cu(2)-O(4) bond length is 1.87 Å. There are a spread of Cu(2)-O(1) bond distances ranging from 1.97-2.21 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1) and three equivalent Cu(2) atoms. In the second O site, O(2) is bonded to two equivalent Ba(1), two equivalent Tm(1), and two equivalent Cu(1) atoms to form a mixture of distorted edge and corner-sharing OBa2Tm2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Tm(1), and two equivalent Cu(1) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Ba(1), one Cu(1), and one Cu(2) atom.