Ca3Al2S(OF)8 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one F(1), two equivalent F(3), and two equivalent F(4) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent F(1), and two equivalent F(2) atoms. Al(1) is bonded to two equivalent O(3), one F(1), one F(2), one F(3), and one F(4) atom to form edge-sharing AlO2F4 octahedra. S(1) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Al(1), and one O(3) atom. In the second O site, O(4) is bonded in a water-like geometry to one Ca(1) and one Ca(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(1) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one S(1) atom. There are four inequivalent F sites. In the first F site, F(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the second F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one Al(1) atom. In the third F site, F(2) is bonded in a bent 150 degrees geometry to one Ca(2) and one Al(1) atom. In the fourth F site, F(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(2), and one Al(1) atom.
Ca3Al2S(OF)8 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one F(1), two equivalent F(3), and two equivalent F(4) atoms. The Ca(1)-O(1) bond length is 2.41 Å. The Ca(1)-O(3) bond length is 2.79 Å. The Ca(1)-O(4) bond length is 2.55 Å. The Ca(1)-F(1) bond length is 2.47 Å. There is one shorter (2.32 Å) and one longer (2.54 Å) Ca(1)-F(3) bond length. There is one shorter (2.34 Å) and one longer (2.38 Å) Ca(1)-F(4) bond length. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent F(1), and two equivalent F(2) atoms. Both Ca(2)-O(1) bond lengths are 2.56 Å. Both Ca(2)-O(4) bond lengths are 2.73 Å. Both Ca(2)-F(1) bond lengths are 2.33 Å. Both Ca(2)-F(2) bond lengths are 2.24 Å. Al(1) is bonded to two equivalent O(3), one F(1), one F(2), one F(3), and one F(4) atom to form edge-sharing AlO2F4 octahedra. There is one shorter (1.87 Å) and one longer (1.88 Å) Al(1)-O(3) bond length. The Al(1)-F(1) bond length is 1.84 Å. The Al(1)-F(2) bond length is 1.74 Å. The Al(1)-F(3) bond length is 1.77 Å. The Al(1)-F(4) bond length is 1.87 Å. S(1) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. Both S(1)-O(1) bond lengths are 1.52 Å. Both S(1)-O(2) bond lengths are 1.48 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Al(1), and one O(3) atom. The O(3)-O(3) bond length is 1.60 Å. In the second O site, O(4) is bonded in a water-like geometry to one Ca(1) and one Ca(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(1) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one S(1) atom. There are four inequivalent F sites. In the first F site, F(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom. In the second F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one Al(1) atom. In the third F site, F(2) is bonded in a bent 150 degrees geometry to one Ca(2) and one Al(1) atom. In the fourth F site, F(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(2), and one Al(1) atom.