Sb2(SO4)3 crystallizes in the monoclinic C2/c space group. Sb(1) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted SbO6 octahedra that share corners with two equivalent S(2)O4 tetrahedra, corners with four equivalent S(1)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. 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(6) atom to form SO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-55°. In the second S site, S(2) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-35°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one S(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one S(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sb(1) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Sb(1) and one S(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Sb(1) and one S(1) atom.
Sb2(SO4)3 crystallizes in the monoclinic C2/c space group. Sb(1) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted SbO6 octahedra that share corners with two equivalent S(2)O4 tetrahedra, corners with four equivalent S(1)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. The Sb(1)-O(1) bond length is 2.44 Å. The Sb(1)-O(3) bond length is 2.16 Å. The Sb(1)-O(5) bond length is 2.13 Å. The Sb(1)-O(6) bond length is 2.18 Å. There is one shorter (2.47 Å) and one longer (2.62 Å) Sb(1)-O(4) bond length. 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(6) atom to form SO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-55°. The S(1)-O(2) bond length is 1.43 Å. The S(1)-O(3) bond length is 1.52 Å. The S(1)-O(4) bond length is 1.52 Å. The S(1)-O(6) bond length is 1.52 Å. In the second S site, S(2) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-35°. Both S(2)-O(1) bond lengths are 1.47 Å. Both S(2)-O(5) bond lengths are 1.51 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one S(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one S(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sb(1) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Sb(1) and one S(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Sb(1) and one S(1) atom.