The material described by MgFe4(PO4)4 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted pentagonal planar geometry to one O(5), one O(6), one O(7), and two equivalent O(1) atoms. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(8) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-36°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to two equivalent Fe(2) and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.519
_cell_length_b   8.811
_cell_length_c   5.227
_cell_angle_alpha   88.521
_cell_angle_beta   105.696
_cell_angle_gamma   89.075
_symmetry_Int_Tables_number   1
_cell_volume   377.447
_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  0.500  1.0
  Fe  Fe1  1  0.156  0.486  0.399  1.0
  Fe  Fe2  1  0.310  0.995  0.026  1.0
  Fe  Fe3  1  0.690  0.005  0.974  1.0
  Fe  Fe4  1  0.844  0.514  0.601  1.0
  P  P5  1  0.247  0.638  0.887  1.0
  P  P6  1  0.307  0.156  0.582  1.0
  P  P7  1  0.693  0.844  0.418  1.0
  P  P8  1  0.753  0.362  0.113  1.0
  O  O9  1  0.083  0.566  0.726  1.0
  O  O10  1  0.183  0.141  0.748  1.0
  O  O11  1  0.214  0.808  0.923  1.0
  O  O12  1  0.248  0.075  0.318  1.0
  O  O13  1  0.366  0.613  0.719  1.0
  O  O14  1  0.298  0.556  0.165  1.0
  O  O15  1  0.345  0.323  0.534  1.0
  O  O16  1  0.459  0.068  0.773  1.0
  O  O17  1  0.541  0.932  0.227  1.0
  O  O18  1  0.655  0.677  0.466  1.0
  O  O19  1  0.702  0.444  0.835  1.0
  O  O20  1  0.634  0.387  0.281  1.0
  O  O21  1  0.752  0.925  0.682  1.0
  O  O22  1  0.786  0.192  0.077  1.0
  O  O23  1  0.817  0.859  0.252  1.0
  O  O24  1  0.917  0.434  0.274  1.0
[/CIF]
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The material described by MgFe4(PO4)4 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted pentagonal planar geometry to one O(5), one O(6), one O(7), and two equivalent O(1) atoms. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(8) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-36°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(2) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to two equivalent Fe(2) and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.519
_cell_length_b   8.811
_cell_length_c   5.227
_cell_angle_alpha   88.521
_cell_angle_beta   105.696
_cell_angle_gamma   89.075
_symmetry_Int_Tables_number   1
_cell_volume   377.447
_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  0.500  1.0
  Fe  Fe1  1  0.156  0.486  0.399  1.0
  Fe  Fe2  1  0.310  0.995  0.026  1.0
  Fe  Fe3  1  0.690  0.005  0.974  1.0
  Fe  Fe4  1  0.844  0.514  0.601  1.0
  P  P5  1  0.247  0.638  0.887  1.0
  P  P6  1  0.307  0.156  0.582  1.0
  P  P7  1  0.693  0.844  0.418  1.0
  P  P8  1  0.753  0.362  0.113  1.0
  O  O9  1  0.083  0.566  0.726  1.0
  O  O10  1  0.183  0.141  0.748  1.0
  O  O11  1  0.214  0.808  0.923  1.0
  O  O12  1  0.248  0.075  0.318  1.0
  O  O13  1  0.366  0.613  0.719  1.0
  O  O14  1  0.298  0.556  0.165  1.0
  O  O15  1  0.345  0.323  0.534  1.0
  O  O16  1  0.459  0.068  0.773  1.0
  O  O17  1  0.541  0.932  0.227  1.0
  O  O18  1  0.655  0.677  0.466  1.0
  O  O19  1  0.702  0.444  0.835  1.0
  O  O20  1  0.634  0.387  0.281  1.0
  O  O21  1  0.752  0.925  0.682  1.0
  O  O22  1  0.786  0.192  0.077  1.0
  O  O23  1  0.817  0.859  0.252  1.0
  O  O24  1  0.917  0.434  0.274  1.0
[/CIF]
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