Materials Data on Al4Cu2O7 by Materials Project
Cu2Al4O7 crystallizes in the cubic F-43m space group. The structure is three-dimensional and consists of four copper molecules and one CuAl4O7 framework. In the CuAl4O7 framework, Cu1+ is bonded to six equivalent O2- atoms to form CuO6 octahedra that share corners with twelve equivalent AlO4 tetrahedra. All Cu–O bond lengths are 2.20 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent CuO6 octahedra and corners with six equivalent AlO4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There is three shorter (1.76 Å) and one longer (1.91 Å) Al–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a tetrahedral geometry to four equivalent Al3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu1+ and two equivalent Al3+ atoms.