The crystal structure described by Mg11Cu2O13 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with four equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mg site, Mg(2) is bonded to two equivalent O(7) and four equivalent O(3) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with five equivalent Mg(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fourth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(6)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth Mg site, Mg(5) is bonded to two equivalent O(4) and four equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, edges with five equivalent Mg(3)O6 octahedra, and edges with six equivalent Mg(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the sixth Mg site, Mg(6) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with four equivalent Mg(3)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are seven inequivalent O sites. In the first O site, O(6) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Mg(6) atoms to form OMg6 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra,  an edgeedge with one O(1)Mg4Cu2 octahedra,  an edgeedge with one O(7)Mg6 octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with four equivalent O(2)Mg4Cu2 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(7) is bonded to two equivalent Mg(2) and four equivalent Mg(6) atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(1) is bonded to two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra, corners with two equivalent O(6)Mg6 octahedra,  an edgeedge with one O(5)Mg6 octahedra,  an edgeedge with one O(6)Mg6 octahedra, edges with two equivalent O(1)Mg4Cu2 octahedra, edges with four equivalent O(2)Mg4Cu2 octahedra, and edges with four equivalent O(4)Mg4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(2) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(3)Mg6 octahedra,  an edgeedge with one O(4)Mg4Cu2 octahedra,  an edgeedge with one O(3)Mg6 octahedra, edges with two equivalent O(2)Mg4Cu2 octahedra, edges with four equivalent O(1)Mg4Cu2 octahedra, and edges with four equivalent O(6)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth O site, O(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(6) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with four equivalent O(3)Mg6 octahedra,  an edgeedge with one O(2)Mg4Cu2 octahedra, edges with three equivalent O(3)Mg6 octahedra, edges with four equivalent O(6)Mg6 octahedra, and edges with four equivalent O(7)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the sixth O site, O(4) is bonded to two equivalent Mg(3), two equivalent Mg(5), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra,  an edgeedge with one O(2)Mg4Cu2 octahedra, edges with two equivalent O(4)Mg4Cu2 octahedra, edges with four equivalent O(1)Mg4Cu2 octahedra, and edges with five equivalent O(5)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the seventh O site, O(5) is bonded to two equivalent Mg(3) and four equivalent Mg(5) atoms to form OMg6 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra,  an edgeedge with one O(1)Mg4Cu2 octahedra, edges with five equivalent O(4)Mg4Cu2 octahedra, and edges with six equivalent O(5)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_Mg11Cu2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   19.644
_cell_length_b   19.644
_cell_length_c   19.644
_cell_angle_alpha   171.162
_cell_angle_beta   167.567
_cell_angle_gamma   15.274
_symmetry_Int_Tables_number   1
_cell_volume   250.734
_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  0.577  0.077  0.500  1.0
  Mg  Mg1  1  0.500  0.000  0.500  1.0
  Mg  Mg2  1  0.423  0.923  0.500  1.0
  Mg  Mg3  1  0.808  0.308  0.500  1.0
  Mg  Mg4  1  0.884  0.384  0.500  1.0
  Mg  Mg5  1  0.731  0.231  0.500  1.0
  Mg  Mg6  1  0.116  0.616  0.500  1.0
  Mg  Mg7  1  0.269  0.769  0.500  1.0
  Mg  Mg8  1  0.961  0.461  0.500  1.0
  Mg  Mg9  1  0.039  0.539  0.500  1.0
  Mg  Mg10  1  0.192  0.692  0.500  1.0
  Cu  Cu11  1  0.654  0.154  0.500  1.0
  Cu  Cu12  1  0.346  0.846  0.500  1.0
  O  O13  1  0.846  0.846  0.000  1.0
  O  O14  1  0.614  0.614  0.000  1.0
  O  O15  1  0.538  0.538  0.000  1.0
  O  O16  1  0.462  0.462  0.000  1.0
  O  O17  1  0.694  0.694  0.000  1.0
  O  O18  1  0.769  0.769  0.000  1.0
  O  O19  1  0.154  0.154  0.000  1.0
  O  O20  1  0.077  0.077  0.000  1.0
  O  O21  1  0.923  0.923  0.000  1.0
  O  O22  1  0.000  0.000  0.000  1.0
  O  O23  1  0.386  0.386  0.000  1.0
  O  O24  1  0.231  0.231  0.000  1.0
  O  O25  1  0.306  0.306  0.000  1.0
[/CIF]
.
The crystal structure described by Mg11Cu2O13 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with four equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mg site, Mg(2) is bonded to two equivalent O(7) and four equivalent O(3) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with five equivalent Mg(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fourth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(6)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth Mg site, Mg(5) is bonded to two equivalent O(4) and four equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, edges with five equivalent Mg(3)O6 octahedra, and edges with six equivalent Mg(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the sixth Mg site, Mg(6) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with four equivalent Mg(3)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are seven inequivalent O sites. In the first O site, O(6) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Mg(6) atoms to form OMg6 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra,  an edgeedge with one O(1)Mg4Cu2 octahedra,  an edgeedge with one O(7)Mg6 octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with four equivalent O(2)Mg4Cu2 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(7) is bonded to two equivalent Mg(2) and four equivalent Mg(6) atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(1) is bonded to two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra, corners with two equivalent O(6)Mg6 octahedra,  an edgeedge with one O(5)Mg6 octahedra,  an edgeedge with one O(6)Mg6 octahedra, edges with two equivalent O(1)Mg4Cu2 octahedra, edges with four equivalent O(2)Mg4Cu2 octahedra, and edges with four equivalent O(4)Mg4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(2) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(3)Mg6 octahedra,  an edgeedge with one O(4)Mg4Cu2 octahedra,  an edgeedge with one O(3)Mg6 octahedra, edges with two equivalent O(2)Mg4Cu2 octahedra, edges with four equivalent O(1)Mg4Cu2 octahedra, and edges with four equivalent O(6)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth O site, O(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(6) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with four equivalent O(3)Mg6 octahedra,  an edgeedge with one O(2)Mg4Cu2 octahedra, edges with three equivalent O(3)Mg6 octahedra, edges with four equivalent O(6)Mg6 octahedra, and edges with four equivalent O(7)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the sixth O site, O(4) is bonded to two equivalent Mg(3), two equivalent Mg(5), and two equivalent Cu(1) atoms to form OMg4Cu2 octahedra that share corners with two equivalent O(2)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra,  an edgeedge with one O(2)Mg4Cu2 octahedra, edges with two equivalent O(4)Mg4Cu2 octahedra, edges with four equivalent O(1)Mg4Cu2 octahedra, and edges with five equivalent O(5)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the seventh O site, O(5) is bonded to two equivalent Mg(3) and four equivalent Mg(5) atoms to form OMg6 octahedra that share corners with two equivalent O(1)Mg4Cu2 octahedra, corners with two equivalent O(4)Mg4Cu2 octahedra, corners with two equivalent O(5)Mg6 octahedra,  an edgeedge with one O(1)Mg4Cu2 octahedra, edges with five equivalent O(4)Mg4Cu2 octahedra, and edges with six equivalent O(5)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_Mg11Cu2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   19.644
_cell_length_b   19.644
_cell_length_c   19.644
_cell_angle_alpha   171.162
_cell_angle_beta   167.567
_cell_angle_gamma   15.274
_symmetry_Int_Tables_number   1
_cell_volume   250.734
_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  0.577  0.077  0.500  1.0
  Mg  Mg1  1  0.500  0.000  0.500  1.0
  Mg  Mg2  1  0.423  0.923  0.500  1.0
  Mg  Mg3  1  0.808  0.308  0.500  1.0
  Mg  Mg4  1  0.884  0.384  0.500  1.0
  Mg  Mg5  1  0.731  0.231  0.500  1.0
  Mg  Mg6  1  0.116  0.616  0.500  1.0
  Mg  Mg7  1  0.269  0.769  0.500  1.0
  Mg  Mg8  1  0.961  0.461  0.500  1.0
  Mg  Mg9  1  0.039  0.539  0.500  1.0
  Mg  Mg10  1  0.192  0.692  0.500  1.0
  Cu  Cu11  1  0.654  0.154  0.500  1.0
  Cu  Cu12  1  0.346  0.846  0.500  1.0
  O  O13  1  0.846  0.846  0.000  1.0
  O  O14  1  0.614  0.614  0.000  1.0
  O  O15  1  0.538  0.538  0.000  1.0
  O  O16  1  0.462  0.462  0.000  1.0
  O  O17  1  0.694  0.694  0.000  1.0
  O  O18  1  0.769  0.769  0.000  1.0
  O  O19  1  0.154  0.154  0.000  1.0
  O  O20  1  0.077  0.077  0.000  1.0
  O  O21  1  0.923  0.923  0.000  1.0
  O  O22  1  0.000  0.000  0.000  1.0
  O  O23  1  0.386  0.386  0.000  1.0
  O  O24  1  0.231  0.231  0.000  1.0
  O  O25  1  0.306  0.306  0.000  1.0
[/CIF]
.