The structure described by Mg4CuO5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with five equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mg site, Mg(2) is bonded to one O(1) and five equivalent O(3) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with eight equivalent Mg(1)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), four equivalent Mg(1), and one Cu(1) atom to form OMg5Cu octahedra that share  a cornercorner with one O(3)Mg6 octahedra, corners with five equivalent O(1)Mg5Cu octahedra, edges with four equivalent O(2)Mg2Cu4 octahedra, edges with four equivalent O(1)Mg5Cu octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second O site, O(2) is bonded to two equivalent Mg(1) and four equivalent Cu(1) atoms to form OMg2Cu4 octahedra that share corners with two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg2Cu4 octahedra, edges with four equivalent O(2)Mg2Cu4 octahedra, and edges with eight equivalent O(1)Mg5Cu octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Mg(1) and five equivalent Mg(2) atoms to form OMg6 octahedra that share  a cornercorner with one O(2)Mg2Cu4 octahedra,  a cornercorner with one O(1)Mg5Cu octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(1)Mg5Cu octahedra, and edges with eight equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Mg4CuO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.838
_cell_length_b   10.838
_cell_length_c   10.838
_cell_angle_alpha   164.048
_cell_angle_beta   164.048
_cell_angle_gamma   22.634
_symmetry_Int_Tables_number   1
_cell_volume   96.154
_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  0.401  0.401  0.000  1.0
  Mg  Mg1  1  0.800  0.800  0.000  1.0
  Mg  Mg2  1  0.200  0.200  0.000  1.0
  Mg  Mg3  1  0.599  0.599  0.000  1.0
  Cu  Cu4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.101  0.101  0.000  1.0
  O  O6  1  0.500  0.500  0.000  1.0
  O  O7  1  0.899  0.899  0.000  1.0
  O  O8  1  0.300  0.300  0.000  1.0
  O  O9  1  0.700  0.700  0.000  1.0
[/CIF]
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The structure described by Mg4CuO5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with five equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mg site, Mg(2) is bonded to one O(1) and five equivalent O(3) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with eight equivalent Mg(1)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), four equivalent Mg(1), and one Cu(1) atom to form OMg5Cu octahedra that share  a cornercorner with one O(3)Mg6 octahedra, corners with five equivalent O(1)Mg5Cu octahedra, edges with four equivalent O(2)Mg2Cu4 octahedra, edges with four equivalent O(1)Mg5Cu octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second O site, O(2) is bonded to two equivalent Mg(1) and four equivalent Cu(1) atoms to form OMg2Cu4 octahedra that share corners with two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg2Cu4 octahedra, edges with four equivalent O(2)Mg2Cu4 octahedra, and edges with eight equivalent O(1)Mg5Cu octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Mg(1) and five equivalent Mg(2) atoms to form OMg6 octahedra that share  a cornercorner with one O(2)Mg2Cu4 octahedra,  a cornercorner with one O(1)Mg5Cu octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(1)Mg5Cu octahedra, and edges with eight equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Mg4CuO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.838
_cell_length_b   10.838
_cell_length_c   10.838
_cell_angle_alpha   164.048
_cell_angle_beta   164.048
_cell_angle_gamma   22.634
_symmetry_Int_Tables_number   1
_cell_volume   96.154
_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  0.401  0.401  0.000  1.0
  Mg  Mg1  1  0.800  0.800  0.000  1.0
  Mg  Mg2  1  0.200  0.200  0.000  1.0
  Mg  Mg3  1  0.599  0.599  0.000  1.0
  Cu  Cu4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.101  0.101  0.000  1.0
  O  O6  1  0.500  0.500  0.000  1.0
  O  O7  1  0.899  0.899  0.000  1.0
  O  O8  1  0.300  0.300  0.000  1.0
  O  O9  1  0.700  0.700  0.000  1.0
[/CIF]
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