The structure described by MgMn4NiO8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with six equivalent Mn(4)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-15°. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-15°. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(3), one Mn(4), and one Ni(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(4), and one Ni(1) atom to form OMgMn3Ni square pyramids that share corners with five equivalent O(2)MgMn3Ni square pyramids and edges with four equivalent O(4)MgMn4 square pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), one Mn(3), and one Ni(1) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom to form OMgMn4 square pyramids that share corners with five equivalent O(4)MgMn4 square pyramids and edges with four equivalent O(2)MgMn3Ni square pyramids. is represented by the CIF file [CIF]
data_MgMn4NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.938
_cell_length_b   6.117
_cell_length_c   6.239
_cell_angle_alpha   90.108
_cell_angle_beta   58.941
_cell_angle_gamma   59.473
_symmetry_Int_Tables_number   1
_cell_volume   156.167
_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  0.000  0.000  0.500  1.0
  Mn  Mn1  1  0.000  0.500  0.500  1.0
  Mn  Mn2  1  0.000  0.000  0.000  1.0
  Mn  Mn3  1  0.500  0.000  0.000  1.0
  Mn  Mn4  1  0.000  0.500  0.000  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.479  0.244  0.800  1.0
  O  O7  1  0.994  0.258  0.781  1.0
  O  O8  1  0.484  0.775  0.797  1.0
  O  O9  1  0.970  0.773  0.744  1.0
  O  O10  1  0.030  0.227  0.256  1.0
  O  O11  1  0.516  0.225  0.203  1.0
  O  O12  1  0.006  0.742  0.219  1.0
  O  O13  1  0.521  0.756  0.200  1.0
[/CIF]
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The structure described by MgMn4NiO8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with six equivalent Mn(4)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-15°. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-15°. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(3), one Mn(4), and one Ni(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(4), and one Ni(1) atom to form OMgMn3Ni square pyramids that share corners with five equivalent O(2)MgMn3Ni square pyramids and edges with four equivalent O(4)MgMn4 square pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), one Mn(3), and one Ni(1) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom to form OMgMn4 square pyramids that share corners with five equivalent O(4)MgMn4 square pyramids and edges with four equivalent O(2)MgMn3Ni square pyramids. is represented by the CIF file [CIF]
data_MgMn4NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.938
_cell_length_b   6.117
_cell_length_c   6.239
_cell_angle_alpha   90.108
_cell_angle_beta   58.941
_cell_angle_gamma   59.473
_symmetry_Int_Tables_number   1
_cell_volume   156.167
_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  0.000  0.000  0.500  1.0
  Mn  Mn1  1  0.000  0.500  0.500  1.0
  Mn  Mn2  1  0.000  0.000  0.000  1.0
  Mn  Mn3  1  0.500  0.000  0.000  1.0
  Mn  Mn4  1  0.000  0.500  0.000  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.479  0.244  0.800  1.0
  O  O7  1  0.994  0.258  0.781  1.0
  O  O8  1  0.484  0.775  0.797  1.0
  O  O9  1  0.970  0.773  0.744  1.0
  O  O10  1  0.030  0.227  0.256  1.0
  O  O11  1  0.516  0.225  0.203  1.0
  O  O12  1  0.006  0.742  0.219  1.0
  O  O13  1  0.521  0.756  0.200  1.0
[/CIF]
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