CaW4O9 crystallizes in the tetragonal P4/n space group. Ca(1) is bonded in a distorted square co-planar geometry to four equivalent O(2) and four equivalent O(3) atoms. W(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 9-25°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to four equivalent W(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1) and two equivalent W(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1) and three equivalent W(1) atoms.
CaW4O9 crystallizes in the tetragonal P4/n space group. Ca(1) is bonded in a distorted square co-planar geometry to four equivalent O(2) and four equivalent O(3) atoms. All Ca(1)-O(2) bond lengths are 2.52 Å. All Ca(1)-O(3) bond lengths are 2.97 Å. W(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 9-25°. The W(1)-O(1) bond length is 2.23 Å. There is one shorter (2.00 Å) and one longer (2.07 Å) W(1)-O(2) bond length. There are a spread of W(1)-O(3) bond distances ranging from 2.06-2.13 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to four equivalent W(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1) and two equivalent W(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1) and three equivalent W(1) atoms.