The material described by MgMn2Fe2(PO4)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(13), one O(15), one O(16), one O(2), and one O(4) atom to form MgO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  an edgeedge with one Mn(2)O6 pentagonal pyramid,  an edgeedge with one Fe(1)O6 pentagonal pyramid,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(2)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted MnO6 pentagonal pyramids that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-58°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(15), and one O(9) atom to form distorted FeO6 pentagonal pyramids that share corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(16) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(1)O6 pentagonal pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(16), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 pentagonal pyramid,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-58°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, corners with two equivalent Mn(2)O6 pentagonal pyramids, and  an edgeedge with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Mn(2)O6 pentagonal pyramid, corners with two equivalent Fe(1)O6 pentagonal pyramids, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(14), and one O(15) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Fe(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-61°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(1), and one P(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mn(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one P(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one P(1) atom. is represented by the CIF file [CIF]
data_MgMn2Fe2(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.239
_cell_length_b   6.049
_cell_length_c   4.891
_cell_angle_alpha   90.221
_cell_angle_beta   88.512
_cell_angle_gamma   89.511
_symmetry_Int_Tables_number   1
_cell_volume   302.799
_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  0.998  0.494  0.005  1.0
  Mn  Mn1  1  0.233  0.762  0.485  1.0
  Mn  Mn2  1  0.294  0.256  0.948  1.0
  Fe  Fe3  1  0.712  0.753  0.034  1.0
  Fe  Fe4  1  0.766  0.242  0.521  1.0
  P  P5  1  0.097  0.252  0.419  1.0
  P  P6  1  0.408  0.752  0.912  1.0
  P  P7  1  0.597  0.253  0.077  1.0
  P  P8  1  0.899  0.742  0.594  1.0
  O  O9  1  0.042  0.737  0.687  1.0
  O  O10  1  0.108  0.276  0.733  1.0
  O  O11  1  0.172  0.049  0.302  1.0
  O  O12  1  0.159  0.455  0.259  1.0
  O  O13  1  0.331  0.560  0.763  1.0
  O  O14  1  0.335  0.953  0.776  1.0
  O  O15  1  0.389  0.744  0.218  1.0
  O  O16  1  0.453  0.254  0.170  1.0
  O  O17  1  0.554  0.747  0.827  1.0
  O  O18  1  0.610  0.253  0.768  1.0
  O  O19  1  0.671  0.046  0.206  1.0
  O  O20  1  0.671  0.455  0.210  1.0
  O  O21  1  0.837  0.539  0.758  1.0
  O  O22  1  0.820  0.936  0.723  1.0
  O  O23  1  0.886  0.723  0.280  1.0
  O  O24  1  0.953  0.258  0.324  1.0
[/CIF]
.
The material described by MgMn2Fe2(PO4)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(13), one O(15), one O(16), one O(2), and one O(4) atom to form MgO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  an edgeedge with one Mn(2)O6 pentagonal pyramid,  an edgeedge with one Fe(1)O6 pentagonal pyramid,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(2)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted MnO6 pentagonal pyramids that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-58°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(15), and one O(9) atom to form distorted FeO6 pentagonal pyramids that share corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(16) atom to form distorted FeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Fe(1)O6 pentagonal pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(16), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 pentagonal pyramid,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-58°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid, corners with two equivalent Mn(2)O6 pentagonal pyramids, and  an edgeedge with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. In the third P site, P(3) is bonded to one O(10), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Mn(2)O6 pentagonal pyramid, corners with two equivalent Fe(1)O6 pentagonal pyramids, and  an edgeedge with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the fourth P site, P(4) is bonded to one O(1), one O(13), one O(14), and one O(15) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O6 pentagonal pyramid,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Fe(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-61°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(1), and one P(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mn(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(3) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one P(4) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one P(1) atom. is represented by the CIF file [CIF]
data_MgMn2Fe2(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.239
_cell_length_b   6.049
_cell_length_c   4.891
_cell_angle_alpha   90.221
_cell_angle_beta   88.512
_cell_angle_gamma   89.511
_symmetry_Int_Tables_number   1
_cell_volume   302.799
_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  0.998  0.494  0.005  1.0
  Mn  Mn1  1  0.233  0.762  0.485  1.0
  Mn  Mn2  1  0.294  0.256  0.948  1.0
  Fe  Fe3  1  0.712  0.753  0.034  1.0
  Fe  Fe4  1  0.766  0.242  0.521  1.0
  P  P5  1  0.097  0.252  0.419  1.0
  P  P6  1  0.408  0.752  0.912  1.0
  P  P7  1  0.597  0.253  0.077  1.0
  P  P8  1  0.899  0.742  0.594  1.0
  O  O9  1  0.042  0.737  0.687  1.0
  O  O10  1  0.108  0.276  0.733  1.0
  O  O11  1  0.172  0.049  0.302  1.0
  O  O12  1  0.159  0.455  0.259  1.0
  O  O13  1  0.331  0.560  0.763  1.0
  O  O14  1  0.335  0.953  0.776  1.0
  O  O15  1  0.389  0.744  0.218  1.0
  O  O16  1  0.453  0.254  0.170  1.0
  O  O17  1  0.554  0.747  0.827  1.0
  O  O18  1  0.610  0.253  0.768  1.0
  O  O19  1  0.671  0.046  0.206  1.0
  O  O20  1  0.671  0.455  0.210  1.0
  O  O21  1  0.837  0.539  0.758  1.0
  O  O22  1  0.820  0.936  0.723  1.0
  O  O23  1  0.886  0.723  0.280  1.0
  O  O24  1  0.953  0.258  0.324  1.0
[/CIF]
.