The compound described by MgCu2(SeO4)2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted CuO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cu(2)O6 octahedra. In the second Cu site, Cu(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cu(1)O6 octahedra. Se(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form distorted SeO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with three equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-64°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Cu(1), one Cu(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Cu(1), and one Se(1) atom. is represented by the CIF file [CIF]
data_MgCu2(SeO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.297
_cell_length_b   5.297
_cell_length_c   6.641
_cell_angle_alpha   94.663
_cell_angle_beta   85.337
_cell_angle_gamma   110.294
_symmetry_Int_Tables_number   1
_cell_volume   173.878
_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  0.500  0.000  1.0
  Cu  Cu1  1  0.000  0.000  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Se  Se3  1  0.670  0.330  0.298  1.0
  Se  Se4  1  0.330  0.670  0.702  1.0
  O  O5  1  0.778  0.222  0.494  1.0
  O  O6  1  0.222  0.778  0.506  1.0
  O  O7  1  0.240  0.327  0.755  1.0
  O  O8  1  0.760  0.673  0.245  1.0
  O  O9  1  0.781  0.219  0.069  1.0
  O  O10  1  0.219  0.781  0.931  1.0
  O  O11  1  0.673  0.760  0.755  1.0
  O  O12  1  0.327  0.240  0.245  1.0
[/CIF]
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The compound described by MgCu2(SeO4)2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted CuO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cu(2)O6 octahedra. In the second Cu site, Cu(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Cu(1)O6 octahedra. Se(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form distorted SeO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with three equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-64°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Cu(1), one Cu(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Cu(1), and one Se(1) atom. is represented by the CIF file [CIF]
data_MgCu2(SeO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.297
_cell_length_b   5.297
_cell_length_c   6.641
_cell_angle_alpha   94.663
_cell_angle_beta   85.337
_cell_angle_gamma   110.294
_symmetry_Int_Tables_number   1
_cell_volume   173.878
_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  0.500  0.000  1.0
  Cu  Cu1  1  0.000  0.000  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Se  Se3  1  0.670  0.330  0.298  1.0
  Se  Se4  1  0.330  0.670  0.702  1.0
  O  O5  1  0.778  0.222  0.494  1.0
  O  O6  1  0.222  0.778  0.506  1.0
  O  O7  1  0.240  0.327  0.755  1.0
  O  O8  1  0.760  0.673  0.245  1.0
  O  O9  1  0.781  0.219  0.069  1.0
  O  O10  1  0.219  0.781  0.931  1.0
  O  O11  1  0.673  0.760  0.755  1.0
  O  O12  1  0.327  0.240  0.245  1.0
[/CIF]
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