Ca5(AsO4)3Cl crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. In the third Ca site, Ca(3) is bonded to one O(2), two equivalent O(3), two equivalent O(4), and one Cl(1) atom to form distorted CaClO5 pentagonal pyramids that share corners with six equivalent Ca(3)ClO5 pentagonal pyramids, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one As(1)O4 tetrahedra. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Ca(3)ClO5 pentagonal pyramids and  an edgeedge with one Ca(3)ClO5 pentagonal pyramid. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one As(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. In the third O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one As(1) atom to form distorted edge-sharing OCa3As tetrahedra. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(3), and one As(1) atom. Cl(1) is bonded in a trigonal non-coplanar geometry to three equivalent Ca(3) atoms.
Ca5(AsO4)3Cl crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Ca(1)-O(1) bond lengths are 2.37 Å. All Ca(1)-O(2) bond lengths are 2.43 Å. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. All Ca(2)-O(1) bond lengths are 2.39 Å. All Ca(2)-O(2) bond lengths are 2.46 Å. All Ca(2)-O(3) bond lengths are 2.89 Å. In the third Ca site, Ca(3) is bonded to one O(2), two equivalent O(3), two equivalent O(4), and one Cl(1) atom to form distorted CaClO5 pentagonal pyramids that share corners with six equivalent Ca(3)ClO5 pentagonal pyramids, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one As(1)O4 tetrahedra. The Ca(3)-O(2) bond length is 2.32 Å. There is one shorter (2.32 Å) and one longer (2.52 Å) Ca(3)-O(3) bond length. There is one shorter (2.35 Å) and one longer (2.47 Å) Ca(3)-O(4) bond length. The Ca(3)-Cl(1) bond length is 2.76 Å. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Ca(3)ClO5 pentagonal pyramids and  an edgeedge with one Ca(3)ClO5 pentagonal pyramid. The As(1)-O(1) bond length is 1.68 Å. The As(1)-O(2) bond length is 1.71 Å. The As(1)-O(3) bond length is 1.70 Å. The As(1)-O(4) bond length is 1.70 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one As(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. In the third O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one As(1) atom to form distorted edge-sharing OCa3As tetrahedra. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(3), and one As(1) atom. Cl(1) is bonded in a trigonal non-coplanar geometry to three equivalent Ca(3) atoms.