Ca4Al6O13 crystallizes in the cubic I-43m space group. Ca(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted CaO4 trigonal pyramids that share corners with six equivalent Al(1)O4 tetrahedra and corners with three equivalent Ca(1)O4 trigonal pyramids. Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra and corners with four equivalent Ca(1)O4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a tetrahedral geometry to four equivalent Ca(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Al(1) atoms.
Ca4Al6O13 crystallizes in the cubic I-43m space group. Ca(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted CaO4 trigonal pyramids that share corners with six equivalent Al(1)O4 tetrahedra and corners with three equivalent Ca(1)O4 trigonal pyramids. The Ca(1)-O(1) bond length is 2.35 Å. All Ca(1)-O(2) bond lengths are 2.27 Å. Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra and corners with four equivalent Ca(1)O4 trigonal pyramids. All Al(1)-O(2) bond lengths are 1.75 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a tetrahedral geometry to four equivalent Ca(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Al(1) atoms.