The compound described by MgEu2Fe2O5 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a square co-planar geometry to one O(1), one O(2), one O(4), and one O(5) atom. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form distorted corner-sharing FeO4 trigonal pyramids. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form distorted corner-sharing FeO4 trigonal pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Eu(2), two equivalent Eu(1), and one Fe(1) atom to form distorted OEu3MgFe trigonal bipyramids that share corners with three equivalent O(3)Eu2Fe2 tetrahedra, corners with two equivalent O(1)Eu3MgFe trigonal bipyramids, corners with three equivalent O(2)Eu3MgFe trigonal bipyramids, corners with four equivalent O(5)Eu2MgFe2 trigonal bipyramids, edges with three equivalent O(4)Eu2MgFe2 trigonal bipyramids, and  a faceface with one O(2)Eu3MgFe trigonal bipyramid. In the second O site, O(2) is bonded to one Mg(1), one Eu(2), two equivalent Eu(1), and one Fe(2) atom to form distorted OEu3MgFe trigonal bipyramids that share corners with three equivalent O(3)Eu2Fe2 tetrahedra, corners with two equivalent O(2)Eu3MgFe trigonal bipyramids, corners with three equivalent O(1)Eu3MgFe trigonal bipyramids, corners with four equivalent O(4)Eu2MgFe2 trigonal bipyramids, edges with three equivalent O(5)Eu2MgFe2 trigonal bipyramids, and  a faceface with one O(1)Eu3MgFe trigonal bipyramid. In the third O site, O(3) is bonded to two equivalent Eu(2), one Fe(1), and one Fe(2) atom to form OEu2Fe2 tetrahedra that share corners with two equivalent O(3)Eu2Fe2 tetrahedra, corners with three equivalent O(1)Eu3MgFe trigonal bipyramids, corners with three equivalent O(2)Eu3MgFe trigonal bipyramids, edges with two equivalent O(4)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(5)Eu2MgFe2 trigonal bipyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Eu(1), one Eu(2), and two equivalent Fe(1) atoms to form distorted OEu2MgFe2 trigonal bipyramids that share  a cornercorner with one O(5)Eu2MgFe2 trigonal bipyramid, corners with two equivalent O(4)Eu2MgFe2 trigonal bipyramids, corners with four equivalent O(2)Eu3MgFe trigonal bipyramids, edges with two equivalent O(3)Eu2Fe2 tetrahedra,  an edgeedge with one O(5)Eu2MgFe2 trigonal bipyramid, and edges with three equivalent O(1)Eu3MgFe trigonal bipyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Eu(1), one Eu(2), and two equivalent Fe(2) atoms to form distorted OEu2MgFe2 trigonal bipyramids that share  a cornercorner with one O(4)Eu2MgFe2 trigonal bipyramid, corners with two equivalent O(5)Eu2MgFe2 trigonal bipyramids, corners with four equivalent O(1)Eu3MgFe trigonal bipyramids, edges with two equivalent O(3)Eu2Fe2 tetrahedra,  an edgeedge with one O(4)Eu2MgFe2 trigonal bipyramid, and edges with three equivalent O(2)Eu3MgFe trigonal bipyramids. is represented by the CIF file [CIF]
data_Eu2MgFe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.083
_cell_length_b   4.069
_cell_length_c   5.819
_cell_angle_alpha   70.661
_cell_angle_beta   90.135
_cell_angle_gamma   89.989
_symmetry_Int_Tables_number   1
_cell_volume   158.257
_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
  Eu  Eu0  1  0.000  0.905  0.851  1.0
  Eu  Eu1  1  0.500  0.227  0.174  1.0
  Mg  Mg2  1  1.000  0.205  0.265  1.0
  Fe  Fe3  1  0.281  0.527  0.598  1.0
  Fe  Fe4  1  0.719  0.527  0.599  1.0
  O  O5  1  0.197  0.356  0.955  1.0
  O  O6  1  0.803  0.356  0.955  1.0
  O  O7  1  0.500  0.631  0.376  1.0
  O  O8  1  0.211  0.067  0.514  1.0
  O  O9  1  0.789  0.067  0.514  1.0
[/CIF]
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The compound described by MgEu2Fe2O5 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a square co-planar geometry to one O(1), one O(2), one O(4), and one O(5) atom. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form distorted corner-sharing FeO4 trigonal pyramids. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form distorted corner-sharing FeO4 trigonal pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Eu(2), two equivalent Eu(1), and one Fe(1) atom to form distorted OEu3MgFe trigonal bipyramids that share corners with three equivalent O(3)Eu2Fe2 tetrahedra, corners with two equivalent O(1)Eu3MgFe trigonal bipyramids, corners with three equivalent O(2)Eu3MgFe trigonal bipyramids, corners with four equivalent O(5)Eu2MgFe2 trigonal bipyramids, edges with three equivalent O(4)Eu2MgFe2 trigonal bipyramids, and  a faceface with one O(2)Eu3MgFe trigonal bipyramid. In the second O site, O(2) is bonded to one Mg(1), one Eu(2), two equivalent Eu(1), and one Fe(2) atom to form distorted OEu3MgFe trigonal bipyramids that share corners with three equivalent O(3)Eu2Fe2 tetrahedra, corners with two equivalent O(2)Eu3MgFe trigonal bipyramids, corners with three equivalent O(1)Eu3MgFe trigonal bipyramids, corners with four equivalent O(4)Eu2MgFe2 trigonal bipyramids, edges with three equivalent O(5)Eu2MgFe2 trigonal bipyramids, and  a faceface with one O(1)Eu3MgFe trigonal bipyramid. In the third O site, O(3) is bonded to two equivalent Eu(2), one Fe(1), and one Fe(2) atom to form OEu2Fe2 tetrahedra that share corners with two equivalent O(3)Eu2Fe2 tetrahedra, corners with three equivalent O(1)Eu3MgFe trigonal bipyramids, corners with three equivalent O(2)Eu3MgFe trigonal bipyramids, edges with two equivalent O(4)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(5)Eu2MgFe2 trigonal bipyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Eu(1), one Eu(2), and two equivalent Fe(1) atoms to form distorted OEu2MgFe2 trigonal bipyramids that share  a cornercorner with one O(5)Eu2MgFe2 trigonal bipyramid, corners with two equivalent O(4)Eu2MgFe2 trigonal bipyramids, corners with four equivalent O(2)Eu3MgFe trigonal bipyramids, edges with two equivalent O(3)Eu2Fe2 tetrahedra,  an edgeedge with one O(5)Eu2MgFe2 trigonal bipyramid, and edges with three equivalent O(1)Eu3MgFe trigonal bipyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Eu(1), one Eu(2), and two equivalent Fe(2) atoms to form distorted OEu2MgFe2 trigonal bipyramids that share  a cornercorner with one O(4)Eu2MgFe2 trigonal bipyramid, corners with two equivalent O(5)Eu2MgFe2 trigonal bipyramids, corners with four equivalent O(1)Eu3MgFe trigonal bipyramids, edges with two equivalent O(3)Eu2Fe2 tetrahedra,  an edgeedge with one O(4)Eu2MgFe2 trigonal bipyramid, and edges with three equivalent O(2)Eu3MgFe trigonal bipyramids. is represented by the CIF file [CIF]
data_Eu2MgFe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.083
_cell_length_b   4.069
_cell_length_c   5.819
_cell_angle_alpha   70.661
_cell_angle_beta   90.135
_cell_angle_gamma   89.989
_symmetry_Int_Tables_number   1
_cell_volume   158.257
_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
  Eu  Eu0  1  0.000  0.905  0.851  1.0
  Eu  Eu1  1  0.500  0.227  0.174  1.0
  Mg  Mg2  1  1.000  0.205  0.265  1.0
  Fe  Fe3  1  0.281  0.527  0.598  1.0
  Fe  Fe4  1  0.719  0.527  0.599  1.0
  O  O5  1  0.197  0.356  0.955  1.0
  O  O6  1  0.803  0.356  0.955  1.0
  O  O7  1  0.500  0.631  0.376  1.0
  O  O8  1  0.211  0.067  0.514  1.0
  O  O9  1  0.789  0.067  0.514  1.0
[/CIF]
.