MnCu2(SO4)2 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with four equivalent S(1)CuO3 tetrahedra and edges with two equivalent Cu(1)SO3 trigonal pyramids. Cu(1) is bonded to one S(1), one O(2), one O(3), and one O(4) atom to form distorted CuSO3 trigonal pyramids that share corners with three equivalent S(1)CuO3 tetrahedra and  an edgeedge with one Mn(1)O6 octahedra. S(1) is bonded to one Cu(1), one O(2), one O(3), and one O(4) atom to form distorted SCuO3 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with three equivalent Cu(1)SO3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 47-54°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mn(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one S(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Cu(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mn(1), one Cu(1), and one S(1) atom.
MnCu2(SO4)2 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with four equivalent S(1)CuO3 tetrahedra and edges with two equivalent Cu(1)SO3 trigonal pyramids. Both Mn(1)-O(1) bond lengths are 1.70 Å. Both Mn(1)-O(3) bond lengths are 2.11 Å. Both Mn(1)-O(4) bond lengths are 2.33 Å. Cu(1) is bonded to one S(1), one O(2), one O(3), and one O(4) atom to form distorted CuSO3 trigonal pyramids that share corners with three equivalent S(1)CuO3 tetrahedra and  an edgeedge with one Mn(1)O6 octahedra. The Cu(1)-S(1) bond length is 2.23 Å. The Cu(1)-O(2) bond length is 1.95 Å. The Cu(1)-O(3) bond length is 2.22 Å. The Cu(1)-O(4) bond length is 2.01 Å. S(1) is bonded to one Cu(1), one O(2), one O(3), and one O(4) atom to form distorted SCuO3 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with three equivalent Cu(1)SO3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 47-54°. The S(1)-O(2) bond length is 1.50 Å. The S(1)-O(3) bond length is 1.54 Å. The S(1)-O(4) bond length is 1.54 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mn(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one S(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Cu(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mn(1), one Cu(1), and one S(1) atom.