The material described by MgFe2(CuO4)2 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O5 trigonal bipyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-50°. In the second Fe site, Fe(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 60-61°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form CuO5 trigonal bipyramids that share corners with two equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(1) atom. In the second O site, O(8) is bonded in a trigonal planar geometry to one Mg(1), one Fe(2), and one Cu(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one Cu(2) atom. In the fifth O site, O(3) is bonded to two equivalent Mg(1), one Fe(2), and one Cu(1) atom to form distorted edge-sharing OMg2FeCu tetrahedra. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(2) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(2) and one Cu(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(2), one Cu(1), and one Cu(2) atom. is represented by the CIF card [CIF]
data_MgFe2(CuO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.416
_cell_length_b   8.289
_cell_length_c   11.983
_cell_angle_alpha   90.000
_cell_angle_beta   92.603
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   636.579
_cell_formula_units_Z   4
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  0.115  0.158  0.047  1.0
  Mg  Mg1  1  0.885  0.842  0.953  1.0
  Mg  Mg2  1  0.885  0.658  0.453  1.0
  Mg  Mg3  1  0.115  0.342  0.547  1.0
  Fe  Fe4  1  0.097  0.460  0.838  1.0
  Fe  Fe5  1  0.097  0.040  0.338  1.0
  Fe  Fe6  1  0.612  0.093  0.132  1.0
  Fe  Fe7  1  0.903  0.960  0.662  1.0
  Fe  Fe8  1  0.388  0.907  0.868  1.0
  Fe  Fe9  1  0.388  0.593  0.368  1.0
  Fe  Fe10  1  0.612  0.407  0.632  1.0
  Fe  Fe11  1  0.903  0.540  0.162  1.0
  Cu  Cu12  1  0.754  0.191  0.880  1.0
  Cu  Cu13  1  0.376  0.059  0.630  1.0
  Cu  Cu14  1  0.624  0.941  0.370  1.0
  Cu  Cu15  1  0.246  0.809  0.120  1.0
  Cu  Cu16  1  0.754  0.309  0.380  1.0
  Cu  Cu17  1  0.376  0.441  0.130  1.0
  Cu  Cu18  1  0.246  0.691  0.620  1.0
  Cu  Cu19  1  0.624  0.559  0.870  1.0
  O  O20  1  0.027  0.239  0.396  1.0
  O  O21  1  0.648  0.014  0.601  1.0
  O  O22  1  0.191  0.576  0.481  1.0
  O  O23  1  0.809  0.076  0.019  1.0
  O  O24  1  0.027  0.261  0.896  1.0
  O  O25  1  0.973  0.761  0.604  1.0
  O  O26  1  0.096  0.112  0.618  1.0
  O  O27  1  0.507  0.885  0.144  1.0
  O  O28  1  0.507  0.615  0.644  1.0
  O  O29  1  0.310  0.873  0.712  1.0
  O  O30  1  0.690  0.373  0.788  1.0
  O  O31  1  0.493  0.115  0.856  1.0
  O  O32  1  0.904  0.888  0.382  1.0
  O  O33  1  0.870  0.521  0.307  1.0
  O  O34  1  0.412  0.264  0.578  1.0
  O  O35  1  0.412  0.236  0.078  1.0
  O  O36  1  0.130  0.021  0.193  1.0
  O  O37  1  0.493  0.385  0.356  1.0
  O  O38  1  0.130  0.479  0.693  1.0
  O  O39  1  0.809  0.424  0.519  1.0
  O  O40  1  0.648  0.486  0.101  1.0
  O  O41  1  0.690  0.127  0.288  1.0
  O  O42  1  0.973  0.739  0.104  1.0
  O  O43  1  0.096  0.388  0.118  1.0
  O  O44  1  0.191  0.924  0.981  1.0
  O  O45  1  0.588  0.764  0.922  1.0
  O  O46  1  0.352  0.986  0.399  1.0
  O  O47  1  0.352  0.514  0.899  1.0
  O  O48  1  0.904  0.612  0.882  1.0
  O  O49  1  0.588  0.736  0.422  1.0
  O  O50  1  0.310  0.627  0.212  1.0
  O  O51  1  0.870  0.979  0.807  1.0
[/CIF]
.
The material described by MgFe2(CuO4)2 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O5 trigonal bipyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 38-50°. In the second Fe site, Fe(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 60-61°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form CuO5 trigonal bipyramids that share corners with two equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(1) atom. In the second O site, O(8) is bonded in a trigonal planar geometry to one Mg(1), one Fe(2), and one Cu(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one Cu(2) atom. In the fifth O site, O(3) is bonded to two equivalent Mg(1), one Fe(2), and one Cu(1) atom to form distorted edge-sharing OMg2FeCu tetrahedra. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Cu(2) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(2) and one Cu(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(2), one Cu(1), and one Cu(2) atom. is represented by the CIF card [CIF]
data_MgFe2(CuO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.416
_cell_length_b   8.289
_cell_length_c   11.983
_cell_angle_alpha   90.000
_cell_angle_beta   92.603
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   636.579
_cell_formula_units_Z   4
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  0.115  0.158  0.047  1.0
  Mg  Mg1  1  0.885  0.842  0.953  1.0
  Mg  Mg2  1  0.885  0.658  0.453  1.0
  Mg  Mg3  1  0.115  0.342  0.547  1.0
  Fe  Fe4  1  0.097  0.460  0.838  1.0
  Fe  Fe5  1  0.097  0.040  0.338  1.0
  Fe  Fe6  1  0.612  0.093  0.132  1.0
  Fe  Fe7  1  0.903  0.960  0.662  1.0
  Fe  Fe8  1  0.388  0.907  0.868  1.0
  Fe  Fe9  1  0.388  0.593  0.368  1.0
  Fe  Fe10  1  0.612  0.407  0.632  1.0
  Fe  Fe11  1  0.903  0.540  0.162  1.0
  Cu  Cu12  1  0.754  0.191  0.880  1.0
  Cu  Cu13  1  0.376  0.059  0.630  1.0
  Cu  Cu14  1  0.624  0.941  0.370  1.0
  Cu  Cu15  1  0.246  0.809  0.120  1.0
  Cu  Cu16  1  0.754  0.309  0.380  1.0
  Cu  Cu17  1  0.376  0.441  0.130  1.0
  Cu  Cu18  1  0.246  0.691  0.620  1.0
  Cu  Cu19  1  0.624  0.559  0.870  1.0
  O  O20  1  0.027  0.239  0.396  1.0
  O  O21  1  0.648  0.014  0.601  1.0
  O  O22  1  0.191  0.576  0.481  1.0
  O  O23  1  0.809  0.076  0.019  1.0
  O  O24  1  0.027  0.261  0.896  1.0
  O  O25  1  0.973  0.761  0.604  1.0
  O  O26  1  0.096  0.112  0.618  1.0
  O  O27  1  0.507  0.885  0.144  1.0
  O  O28  1  0.507  0.615  0.644  1.0
  O  O29  1  0.310  0.873  0.712  1.0
  O  O30  1  0.690  0.373  0.788  1.0
  O  O31  1  0.493  0.115  0.856  1.0
  O  O32  1  0.904  0.888  0.382  1.0
  O  O33  1  0.870  0.521  0.307  1.0
  O  O34  1  0.412  0.264  0.578  1.0
  O  O35  1  0.412  0.236  0.078  1.0
  O  O36  1  0.130  0.021  0.193  1.0
  O  O37  1  0.493  0.385  0.356  1.0
  O  O38  1  0.130  0.479  0.693  1.0
  O  O39  1  0.809  0.424  0.519  1.0
  O  O40  1  0.648  0.486  0.101  1.0
  O  O41  1  0.690  0.127  0.288  1.0
  O  O42  1  0.973  0.739  0.104  1.0
  O  O43  1  0.096  0.388  0.118  1.0
  O  O44  1  0.191  0.924  0.981  1.0
  O  O45  1  0.588  0.764  0.922  1.0
  O  O46  1  0.352  0.986  0.399  1.0
  O  O47  1  0.352  0.514  0.899  1.0
  O  O48  1  0.904  0.612  0.882  1.0
  O  O49  1  0.588  0.736  0.422  1.0
  O  O50  1  0.310  0.627  0.212  1.0
  O  O51  1  0.870  0.979  0.807  1.0
[/CIF]
.