Ca4Al6WO16 crystallizes in the orthorhombic Aem2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(9) atoms. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), one O(6), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. W(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(5) and two equivalent O(7) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(4), one O(6), one O(8), and one O(9) atom to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to two equivalent O(6) and two equivalent O(9) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the fourth Al site, Al(4) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form distorted corner-sharing AlO4 tetrahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(3), one Al(3), and one Al(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Al(3), and one Al(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(3) and two equivalent Al(3) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and two equivalent Al(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(1), one Ca(2), and one W(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(2), one Al(1), and one Al(2) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ca(3) and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Al(1), and one Al(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(1), one Al(1), and one Al(2) atom.
Ca4Al6WO16 crystallizes in the orthorhombic Aem2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(9) atoms. There is one shorter (2.38 Å) and one longer (2.91 Å) Ca(1)-O(4) bond length. Both Ca(1)-O(5) bond lengths are 2.84 Å. Both Ca(1)-O(9) bond lengths are 2.29 Å. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), one O(6), and two equivalent O(8) atoms. The Ca(2)-O(1) bond length is 2.34 Å. The Ca(2)-O(2) bond length is 2.84 Å. The Ca(2)-O(5) bond length is 2.44 Å. The Ca(2)-O(6) bond length is 2.30 Å. There is one shorter (2.39 Å) and one longer (2.81 Å) Ca(2)-O(8) bond length. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. Both Ca(3)-O(1) bond lengths are 3.04 Å. Both Ca(3)-O(2) bond lengths are 2.37 Å. There is one shorter (2.41 Å) and one longer (2.83 Å) Ca(3)-O(3) bond length. Both Ca(3)-O(7) bond lengths are 2.55 Å. W(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(5) and two equivalent O(7) atoms. Both W(1)-O(5) bond lengths are 1.84 Å. Both W(1)-O(7) bond lengths are 1.93 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(4), one O(6), one O(8), and one O(9) atom to form corner-sharing AlO4 tetrahedra. The Al(1)-O(4) bond length is 1.79 Å. The Al(1)-O(6) bond length is 1.76 Å. The Al(1)-O(8) bond length is 1.77 Å. The Al(1)-O(9) bond length is 1.75 Å. In the second Al site, Al(2) is bonded to two equivalent O(6) and two equivalent O(9) atoms to form corner-sharing AlO4 tetrahedra. Both Al(2)-O(6) bond lengths are 1.78 Å. Both Al(2)-O(9) bond lengths are 1.78 Å. In the third Al site, Al(3) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form corner-sharing AlO4 tetrahedra. The Al(3)-O(1) bond length is 1.74 Å. The Al(3)-O(2) bond length is 1.75 Å. The Al(3)-O(3) bond length is 1.75 Å. The Al(3)-O(8) bond length is 1.77 Å. In the fourth Al site, Al(4) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form distorted corner-sharing AlO4 tetrahedra. Both Al(4)-O(1) bond lengths are 1.77 Å. Both Al(4)-O(2) bond lengths are 1.78 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(3), one Al(3), and one Al(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Al(3), and one Al(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(3) and two equivalent Al(3) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and two equivalent Al(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(1), one Ca(2), and one W(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(2), one Al(1), and one Al(2) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ca(3) and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Al(1), and one Al(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(1), one Al(1), and one Al(2) atom.