Cr2(SO4)3 crystallizes in the trigonal R-3 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. There are four inequivalent O sites. In the first O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the third O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom.
Cr2(SO4)3 crystallizes in the trigonal R-3 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. All Cr(1)-O(1) bond lengths are 1.98 Å. All Cr(1)-O(4) bond lengths are 1.95 Å. In the second Cr site, Cr(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. All Cr(2)-O(2) bond lengths are 1.97 Å. All Cr(2)-O(3) bond lengths are 1.96 Å. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. The S(1)-O(1) bond length is 1.46 Å. The S(1)-O(2) bond length is 1.46 Å. The S(1)-O(3) bond length is 1.46 Å. The S(1)-O(4) bond length is 1.48 Å. There are four inequivalent O sites. In the first O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the third O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom.