Ca5S3O12F crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), four equivalent O(3), and one F(1) atom to form distorted CaO6F pentagonal bipyramids that share corners with six equivalent Ca(1)O6F pentagonal bipyramids, corners with four equivalent S(1)O4 tetrahedra, and  an edgeedge with one S(1)O4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. S(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted SO4 tetrahedra that share corners with four equivalent Ca(1)O6F pentagonal bipyramids and  an edgeedge with one Ca(1)O6F pentagonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Ca(2), and one S(1) atom to form a mixture of corner and edge-sharing OCa3S tetrahedra. In the second O site, O(2) is bonded to one Ca(1), two equivalent Ca(2), and one S(1) atom to form a mixture of corner and edge-sharing OCa3S tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one S(1) atom. F(1) is bonded in a trigonal planar geometry to three equivalent Ca(1) atoms.
Ca5S3O12F crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), four equivalent O(3), and one F(1) atom to form distorted CaO6F pentagonal bipyramids that share corners with six equivalent Ca(1)O6F pentagonal bipyramids, corners with four equivalent S(1)O4 tetrahedra, and  an edgeedge with one S(1)O4 tetrahedra. The Ca(1)-O(1) bond length is 2.35 Å. The Ca(1)-O(2) bond length is 2.44 Å. There are two shorter (2.45 Å) and two longer (2.53 Å) Ca(1)-O(3) bond lengths. The Ca(1)-F(1) bond length is 2.39 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Ca(2)-O(1) bond lengths are 2.37 Å. All Ca(2)-O(2) bond lengths are 2.51 Å. S(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted SO4 tetrahedra that share corners with four equivalent Ca(1)O6F pentagonal bipyramids and  an edgeedge with one Ca(1)O6F pentagonal bipyramid. The S(1)-O(1) bond length is 1.79 Å. The S(1)-O(2) bond length is 1.64 Å. Both S(1)-O(3) bond lengths are 1.54 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Ca(2), and one S(1) atom to form a mixture of corner and edge-sharing OCa3S tetrahedra. In the second O site, O(2) is bonded to one Ca(1), two equivalent Ca(2), and one S(1) atom to form a mixture of corner and edge-sharing OCa3S tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one S(1) atom. F(1) is bonded in a trigonal planar geometry to three equivalent Ca(1) atoms.