The structure described by MgAl2(CuO2)4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted MgO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(3)O6 octahedra, and faces with two equivalent Al(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 7-26°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Cu(2)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-26°. In the second Cu site, Cu(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. In the third Cu site, Cu(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, and edges with two equivalent Cu(3)O6 octahedra. Al(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted AlO4 trigonal pyramids that share corners with three equivalent Cu(1)O6 octahedra, corners with three equivalent Cu(2)O6 octahedra, corners with six equivalent Cu(3)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-70°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cu(1), one Cu(2), one Cu(3), and one Al(1) atom to form distorted OMgAlCu3 square pyramids that share corners with five equivalent O(1)MgAlCu3 square pyramids, corners with three equivalent O(2)AlCu3 tetrahedra, edges with three equivalent O(1)MgAlCu3 square pyramids, and  an edgeedge with one O(2)AlCu3 tetrahedra. In the second O site, O(2) is bonded to one Cu(2), two equivalent Cu(3), and one Al(1) atom to form distorted OAlCu3 tetrahedra that share corners with six equivalent O(1)MgAlCu3 square pyramids, corners with three equivalent O(2)AlCu3 tetrahedra, and edges with two equivalent O(1)MgAlCu3 square pyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Cu(1), two equivalent Cu(3), and one Al(1) atom. is represented by the CIF card [CIF]
data_MgAl2(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.879
_cell_length_b   6.513
_cell_length_c   5.879
_cell_angle_alpha   57.736
_cell_angle_beta   61.160
_cell_angle_gamma   57.736
_symmetry_Int_Tables_number   1
_cell_volume   154.676
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.500  0.000  0.500  1.0
  Al  Al1  1  0.650  0.533  0.650  1.0
  Al  Al2  1  0.350  0.467  0.350  1.0
  Cu  Cu3  1  0.000  0.500  0.000  1.0
  Cu  Cu4  1  0.000  0.000  0.000  1.0
  Cu  Cu5  1  0.500  0.000  0.000  1.0
  Cu  Cu6  1  0.000  0.000  0.500  1.0
  O  O7  1  0.275  0.747  0.723  1.0
  O  O8  1  0.277  0.253  0.725  1.0
  O  O9  1  0.236  0.811  0.236  1.0
  O  O10  1  0.245  0.324  0.245  1.0
  O  O11  1  0.723  0.747  0.275  1.0
  O  O12  1  0.725  0.253  0.277  1.0
  O  O13  1  0.764  0.189  0.764  1.0
  O  O14  1  0.755  0.676  0.755  1.0
[/CIF]
.
The structure described by MgAl2(CuO2)4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted MgO6 octahedra that share corners with six equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(3)O6 octahedra, and faces with two equivalent Al(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 7-26°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Cu(2)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-26°. In the second Cu site, Cu(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CuO6 octahedra that share corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. In the third Cu site, Cu(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with six equivalent Al(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, and edges with two equivalent Cu(3)O6 octahedra. Al(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted AlO4 trigonal pyramids that share corners with three equivalent Cu(1)O6 octahedra, corners with three equivalent Cu(2)O6 octahedra, corners with six equivalent Cu(3)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-70°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cu(1), one Cu(2), one Cu(3), and one Al(1) atom to form distorted OMgAlCu3 square pyramids that share corners with five equivalent O(1)MgAlCu3 square pyramids, corners with three equivalent O(2)AlCu3 tetrahedra, edges with three equivalent O(1)MgAlCu3 square pyramids, and  an edgeedge with one O(2)AlCu3 tetrahedra. In the second O site, O(2) is bonded to one Cu(2), two equivalent Cu(3), and one Al(1) atom to form distorted OAlCu3 tetrahedra that share corners with six equivalent O(1)MgAlCu3 square pyramids, corners with three equivalent O(2)AlCu3 tetrahedra, and edges with two equivalent O(1)MgAlCu3 square pyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Cu(1), two equivalent Cu(3), and one Al(1) atom. is represented by the CIF card [CIF]
data_MgAl2(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.879
_cell_length_b   6.513
_cell_length_c   5.879
_cell_angle_alpha   57.736
_cell_angle_beta   61.160
_cell_angle_gamma   57.736
_symmetry_Int_Tables_number   1
_cell_volume   154.676
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Mg  Mg0  1  0.500  0.000  0.500  1.0
  Al  Al1  1  0.650  0.533  0.650  1.0
  Al  Al2  1  0.350  0.467  0.350  1.0
  Cu  Cu3  1  0.000  0.500  0.000  1.0
  Cu  Cu4  1  0.000  0.000  0.000  1.0
  Cu  Cu5  1  0.500  0.000  0.000  1.0
  Cu  Cu6  1  0.000  0.000  0.500  1.0
  O  O7  1  0.275  0.747  0.723  1.0
  O  O8  1  0.277  0.253  0.725  1.0
  O  O9  1  0.236  0.811  0.236  1.0
  O  O10  1  0.245  0.324  0.245  1.0
  O  O11  1  0.723  0.747  0.275  1.0
  O  O12  1  0.725  0.253  0.277  1.0
  O  O13  1  0.764  0.189  0.764  1.0
  O  O14  1  0.755  0.676  0.755  1.0
[/CIF]
.