Ca3WO5Cl2 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), one Cl(2), and two equivalent Cl(1) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to two equivalent O(2), two equivalent O(3), one Cl(1), and one Cl(2) atom. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), one Cl(1), and three equivalent Cl(2) atoms. W(1) is bonded in a distorted trigonal bipyramidal geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one W(1) atom. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one W(1) atom to form OCa3W tetrahedra that share corners with four equivalent O(3)Ca3W tetrahedra, corners with four equivalent Cl(1)Ca4 trigonal pyramids, edges with two equivalent O(2)Ca3W tetrahedra, and edges with two equivalent O(3)Ca3W tetrahedra. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Ca(3), and one W(1) atom to form OCa3W tetrahedra that share corners with four equivalent O(2)Ca3W tetrahedra, corners with two equivalent Cl(1)Ca4 trigonal pyramids, edges with two equivalent O(2)Ca3W tetrahedra, edges with two equivalent O(3)Ca3W tetrahedra, and  an edgeedge with one Cl(1)Ca4 trigonal pyramid. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Ca(2), one Ca(3), and two equivalent Ca(1) atoms to form distorted ClCa4 trigonal pyramids that share corners with four equivalent O(3)Ca3W tetrahedra, corners with eight equivalent O(2)Ca3W tetrahedra, corners with two equivalent Cl(1)Ca4 trigonal pyramids, and edges with two equivalent O(3)Ca3W tetrahedra. In the second Cl site, Cl(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), and three equivalent Ca(3) atoms.
Ca3WO5Cl2 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), one Cl(2), and two equivalent Cl(1) atoms. The Ca(1)-O(1) bond length is 2.34 Å. Both Ca(1)-O(2) bond lengths are 2.42 Å. Both Ca(1)-O(3) bond lengths are 2.45 Å. The Ca(1)-Cl(2) bond length is 3.16 Å. Both Ca(1)-Cl(1) bond lengths are 3.16 Å. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to two equivalent O(2), two equivalent O(3), one Cl(1), and one Cl(2) atom. Both Ca(2)-O(2) bond lengths are 2.34 Å. Both Ca(2)-O(3) bond lengths are 2.31 Å. The Ca(2)-Cl(1) bond length is 2.72 Å. The Ca(2)-Cl(2) bond length is 3.35 Å. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), one Cl(1), and three equivalent Cl(2) atoms. Both Ca(3)-O(2) bond lengths are 2.34 Å. Both Ca(3)-O(3) bond lengths are 2.37 Å. The Ca(3)-Cl(1) bond length is 2.75 Å. There is one shorter (2.86 Å) and two longer (3.27 Å) Ca(3)-Cl(2) bond lengths. W(1) is bonded in a distorted trigonal bipyramidal geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. The W(1)-O(1) bond length is 1.78 Å. Both W(1)-O(2) bond lengths are 1.95 Å. Both W(1)-O(3) bond lengths are 1.93 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one W(1) atom. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one W(1) atom to form OCa3W tetrahedra that share corners with four equivalent O(3)Ca3W tetrahedra, corners with four equivalent Cl(1)Ca4 trigonal pyramids, edges with two equivalent O(2)Ca3W tetrahedra, and edges with two equivalent O(3)Ca3W tetrahedra. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Ca(3), and one W(1) atom to form OCa3W tetrahedra that share corners with four equivalent O(2)Ca3W tetrahedra, corners with two equivalent Cl(1)Ca4 trigonal pyramids, edges with two equivalent O(2)Ca3W tetrahedra, edges with two equivalent O(3)Ca3W tetrahedra, and  an edgeedge with one Cl(1)Ca4 trigonal pyramid. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Ca(2), one Ca(3), and two equivalent Ca(1) atoms to form distorted ClCa4 trigonal pyramids that share corners with four equivalent O(3)Ca3W tetrahedra, corners with eight equivalent O(2)Ca3W tetrahedra, corners with two equivalent Cl(1)Ca4 trigonal pyramids, and edges with two equivalent O(3)Ca3W tetrahedra. In the second Cl site, Cl(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), and three equivalent Ca(3) atoms.