Mn(SO4)2 crystallizes in the trigonal R3 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the second Mn site, Mn(2) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the third Mn site, Mn(3) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. In the second S site, S(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-48°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a single-bond geometry to one S(1) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Mn(3) and one S(2) atom. In the third O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one S(2) atom. In the fourth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one S(2) atom. In the fifth O site, O(8) is bonded in a bent 150 degrees geometry to one Mn(2) and one S(1) atom. In the sixth O site, O(1) is bonded in a single-bond geometry to one S(2) atom. In the seventh O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one S(1) atom. In the eighth O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(3) and one S(1) atom.
Mn(SO4)2 crystallizes in the trigonal R3 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. All Mn(1)-O(2) bond lengths are 2.02 Å. All Mn(1)-O(6) bond lengths are 1.97 Å. In the second Mn site, Mn(2) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. All Mn(2)-O(7) bond lengths are 2.04 Å. All Mn(2)-O(8) bond lengths are 2.00 Å. In the third Mn site, Mn(3) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form MnO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. All Mn(3)-O(3) bond lengths are 1.94 Å. All Mn(3)-O(5) bond lengths are 1.99 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. The S(1)-O(2) bond length is 1.51 Å. The S(1)-O(3) bond length is 1.52 Å. The S(1)-O(4) bond length is 1.43 Å. The S(1)-O(8) bond length is 1.51 Å. In the second S site, S(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-48°. The S(2)-O(1) bond length is 1.43 Å. The S(2)-O(5) bond length is 1.50 Å. The S(2)-O(6) bond length is 1.53 Å. The S(2)-O(7) bond length is 1.50 Å. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a single-bond geometry to one S(1) atom. In the second O site, O(5) is bonded in a bent 150 degrees geometry to one Mn(3) and one S(2) atom. In the third O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one S(2) atom. In the fourth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one S(2) atom. In the fifth O site, O(8) is bonded in a bent 150 degrees geometry to one Mn(2) and one S(1) atom. In the sixth O site, O(1) is bonded in a single-bond geometry to one S(2) atom. In the seventh O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one S(1) atom. In the eighth O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(3) and one S(1) atom.