CaSn(SO4)3 crystallizes in the trigonal R3c space group. Ca(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form CaO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. Sn(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form SnO6 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 Ca(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-39°. There are four inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Sn(1) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one S(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one S(1) atom. In the fourth O site, O(1) is bonded in a distorted linear geometry to one Ca(1) and one S(1) atom.
CaSn(SO4)3 crystallizes in the trigonal R3c space group. Ca(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form CaO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. All Ca(1)-O(1) bond lengths are 2.26 Å. All Ca(1)-O(3) bond lengths are 2.25 Å. Sn(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form SnO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. All Sn(1)-O(2) bond lengths are 2.11 Å. All Sn(1)-O(4) bond lengths are 2.10 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 Ca(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-39°. The S(1)-O(1) bond length is 1.44 Å. The S(1)-O(2) bond length is 1.54 Å. The S(1)-O(3) bond length is 1.45 Å. The S(1)-O(4) bond length is 1.52 Å. There are four inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Sn(1) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one S(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one S(1) atom. In the fourth O site, O(1) is bonded in a distorted linear geometry to one Ca(1) and one S(1) atom.