The compound described by MgEu4(Fe2O5)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted MgO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  a cornercorner with one Fe(3)O4 trigonal pyramid,  an edgeedge with one Fe(4)O4 tetrahedra, and  a faceface with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 28-35°. There are four inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), one O(9), and two equivalent O(5) atoms. In the second Eu site, Eu(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. In the third Eu site, Eu(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(9), and two equivalent O(8) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra, and  a cornercorner with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-35°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra, and  a cornercorner with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-35°. In the third Fe site, Fe(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-56°. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Fe(3)O4 trigonal pyramids, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-56°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(4)Eu4Fe2 octahedra, corners with two equivalent O(10)Eu2MgFe2 square pyramids, corners with two equivalent O(9)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(4)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(10)Eu2MgFe2 square pyramids, corners with two equivalent O(9)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(1)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Mg(1), one Eu(3), two equivalent Eu(1), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Eu(2), one Eu(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Mg(1), one Eu(1), one Eu(3), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Mg(1), one Eu(2), two equivalent Eu(4), one Fe(2), and one Fe(3) atom. In the ninth O site, O(9) is bonded to one Mg(1), one Eu(1), one Eu(4), one Fe(3), and one Fe(4) atom to form distorted OEu2MgFe2 trigonal bipyramids that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(4)Eu4Fe2 octahedra, and corners with three equivalent O(10)Eu2MgFe2 square pyramids. The corner-sharing octahedral tilt angles range from 30-69°. In the tenth O site, O(10) is bonded to one Mg(1), one Eu(2), one Eu(3), one Fe(3), and one Fe(4) atom to form distorted OEu2MgFe2 square pyramids that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(4)Eu4Fe2 octahedra, and corners with three equivalent O(9)Eu2MgFe2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 50-58°. is represented by the CIF file [CIF]
data_Eu4Mg(Fe2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.484
_cell_length_b   5.850
_cell_length_c   8.975
_cell_angle_alpha   108.590
_cell_angle_beta   107.391
_cell_angle_gamma   90.976
_symmetry_Int_Tables_number   1
_cell_volume   258.385
_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  0.619  0.139  0.216  1.0
  Eu  Eu1  1  0.409  0.886  0.806  1.0
  Eu  Eu2  1  0.103  0.579  0.194  1.0
  Eu  Eu3  1  0.904  0.422  0.784  1.0
  Mg  Mg4  1  0.042  0.531  0.500  1.0
  Fe  Fe5  1  0.017  0.009  0.006  1.0
  Fe  Fe6  1  0.511  0.503  0.995  1.0
  Fe  Fe7  1  0.239  0.139  0.500  1.0
  Fe  Fe8  1  0.685  0.849  0.500  1.0
  O  O9  1  0.255  0.250  0.987  1.0
  O  O10  1  0.286  0.774  0.037  1.0
  O  O11  1  0.746  0.239  0.963  1.0
  O  O12  1  0.769  0.765  0.012  1.0
  O  O13  1  0.142  0.233  0.299  1.0
  O  O14  1  0.933  0.761  0.691  1.0
  O  O15  1  0.742  0.570  0.308  1.0
  O  O16  1  0.342  0.433  0.701  1.0
  O  O17  1  0.820  0.172  0.500  1.0
  O  O18  1  0.312  0.795  0.500  1.0
[/CIF]
.
The compound described by MgEu4(Fe2O5)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted MgO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  a cornercorner with one Fe(3)O4 trigonal pyramid,  an edgeedge with one Fe(4)O4 tetrahedra, and  a faceface with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 28-35°. There are four inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), one O(9), and two equivalent O(5) atoms. In the second Eu site, Eu(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. In the third Eu site, Eu(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(9), and two equivalent O(8) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra, and  a cornercorner with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-35°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra, and  a cornercorner with one Fe(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 6-35°. In the third Fe site, Fe(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-56°. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Fe(3)O4 trigonal pyramids, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-56°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(4)Eu4Fe2 octahedra, corners with two equivalent O(10)Eu2MgFe2 square pyramids, corners with two equivalent O(9)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(4)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Fe(1), and one Fe(2) atom to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(10)Eu2MgFe2 square pyramids, corners with two equivalent O(9)Eu2MgFe2 trigonal bipyramids, and edges with two equivalent O(1)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Mg(1), one Eu(3), two equivalent Eu(1), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Eu(2), one Eu(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Mg(1), one Eu(1), one Eu(3), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Mg(1), one Eu(2), two equivalent Eu(4), one Fe(2), and one Fe(3) atom. In the ninth O site, O(9) is bonded to one Mg(1), one Eu(1), one Eu(4), one Fe(3), and one Fe(4) atom to form distorted OEu2MgFe2 trigonal bipyramids that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(4)Eu4Fe2 octahedra, and corners with three equivalent O(10)Eu2MgFe2 square pyramids. The corner-sharing octahedral tilt angles range from 30-69°. In the tenth O site, O(10) is bonded to one Mg(1), one Eu(2), one Eu(3), one Fe(3), and one Fe(4) atom to form distorted OEu2MgFe2 square pyramids that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with two equivalent O(4)Eu4Fe2 octahedra, and corners with three equivalent O(9)Eu2MgFe2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 50-58°. is represented by the CIF file [CIF]
data_Eu4Mg(Fe2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.484
_cell_length_b   5.850
_cell_length_c   8.975
_cell_angle_alpha   108.590
_cell_angle_beta   107.391
_cell_angle_gamma   90.976
_symmetry_Int_Tables_number   1
_cell_volume   258.385
_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  0.619  0.139  0.216  1.0
  Eu  Eu1  1  0.409  0.886  0.806  1.0
  Eu  Eu2  1  0.103  0.579  0.194  1.0
  Eu  Eu3  1  0.904  0.422  0.784  1.0
  Mg  Mg4  1  0.042  0.531  0.500  1.0
  Fe  Fe5  1  0.017  0.009  0.006  1.0
  Fe  Fe6  1  0.511  0.503  0.995  1.0
  Fe  Fe7  1  0.239  0.139  0.500  1.0
  Fe  Fe8  1  0.685  0.849  0.500  1.0
  O  O9  1  0.255  0.250  0.987  1.0
  O  O10  1  0.286  0.774  0.037  1.0
  O  O11  1  0.746  0.239  0.963  1.0
  O  O12  1  0.769  0.765  0.012  1.0
  O  O13  1  0.142  0.233  0.299  1.0
  O  O14  1  0.933  0.761  0.691  1.0
  O  O15  1  0.742  0.570  0.308  1.0
  O  O16  1  0.342  0.433  0.701  1.0
  O  O17  1  0.820  0.172  0.500  1.0
  O  O18  1  0.312  0.795  0.500  1.0
[/CIF]
.