The material described by MgMn5O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. In the second Mn site, Mn(2) is bonded to one O(1), 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 two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and  a faceface with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-54°. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  a faceface with one Mn(2)O6 pentagonal pyramid. In the fourth Mn site, Mn(4) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), one O(5), and one O(8) atom. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Mn(5) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(4)MgMn4 trigonal bipyramids, corners with three equivalent O(8)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(8)MgMn4 trigonal bipyramid, edges with two equivalent O(5)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mn(1), one Mn(3), and one Mn(5) atom. In the third O site, O(3) is bonded to one Mn(1), one Mn(2), one Mn(3), and one Mn(5) atom to form distorted OMn4 trigonal pyramids that share  a cornercorner with one O(1)MgMn4 trigonal bipyramid,  a cornercorner with one O(4)MgMn4 trigonal bipyramid,  a cornercorner with one O(5)MgMn4 trigonal bipyramid,  a cornercorner with one O(8)MgMn4 trigonal bipyramid, corners with three equivalent O(6)MgMn3 trigonal pyramids,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, and  an edgeedge with one O(8)MgMn4 trigonal bipyramid. 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 trigonal bipyramids that share corners with two equivalent O(1)MgMn4 trigonal bipyramids, corners with three equivalent O(5)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, edges with two equivalent O(8)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(8)MgMn4 trigonal bipyramids, corners with three equivalent O(4)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(8)MgMn4 trigonal bipyramid, edges with two equivalent O(1)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(1), one Mn(1), one Mn(2), and one Mn(5) atom to form OMgMn3 trigonal pyramids that share  a cornercorner with one O(1)MgMn4 trigonal bipyramid,  a cornercorner with one O(4)MgMn4 trigonal bipyramid,  a cornercorner with one O(5)MgMn4 trigonal bipyramid,  a cornercorner with one O(8)MgMn4 trigonal bipyramid, corners with three equivalent O(3)Mn4 trigonal pyramids,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, and  an edgeedge with one O(8)MgMn4 trigonal bipyramid. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Mn(5) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Mn(5) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(5)MgMn4 trigonal bipyramids, corners with three equivalent O(1)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, edges with two equivalent O(4)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. is represented by the CIF file [CIF]
data_MgMn5O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.855
_cell_length_b   7.883
_cell_length_c   6.806
_cell_angle_alpha   89.707
_cell_angle_beta   50.855
_cell_angle_gamma   50.656
_symmetry_Int_Tables_number   1
_cell_volume   165.958
_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  0.821  0.968  0.719  1.0
  Mn  Mn1  1  0.993  0.513  0.484  1.0
  Mn  Mn2  1  0.705  0.302  0.283  1.0
  Mn  Mn3  1  0.279  0.995  0.230  1.0
  Mn  Mn4  1  0.034  0.492  0.982  1.0
  Mn  Mn5  1  0.491  0.513  0.981  1.0
  O  O6  1  0.606  0.277  0.656  1.0
  O  O7  1  0.102  0.238  0.553  1.0
  O  O8  1  0.365  0.809  0.943  1.0
  O  O9  1  0.967  0.671  0.789  1.0
  O  O10  1  0.135  0.272  0.132  1.0
  O  O11  1  0.614  0.241  0.069  1.0
  O  O12  1  0.905  0.769  0.402  1.0
  O  O13  1  0.472  0.689  0.278  1.0
[/CIF]
.
The material described by MgMn5O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. In the second Mn site, Mn(2) is bonded to one O(1), 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 two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and  a faceface with one Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-54°. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(5)O6 octahedra, and  a faceface with one Mn(2)O6 pentagonal pyramid. In the fourth Mn site, Mn(4) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), one O(5), and one O(8) atom. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 pentagonal pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and  an edgeedge with one Mn(2)O6 pentagonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Mn(5) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(4)MgMn4 trigonal bipyramids, corners with three equivalent O(8)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(8)MgMn4 trigonal bipyramid, edges with two equivalent O(5)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mn(1), one Mn(3), and one Mn(5) atom. In the third O site, O(3) is bonded to one Mn(1), one Mn(2), one Mn(3), and one Mn(5) atom to form distorted OMn4 trigonal pyramids that share  a cornercorner with one O(1)MgMn4 trigonal bipyramid,  a cornercorner with one O(4)MgMn4 trigonal bipyramid,  a cornercorner with one O(5)MgMn4 trigonal bipyramid,  a cornercorner with one O(8)MgMn4 trigonal bipyramid, corners with three equivalent O(6)MgMn3 trigonal pyramids,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, and  an edgeedge with one O(8)MgMn4 trigonal bipyramid. 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 trigonal bipyramids that share corners with two equivalent O(1)MgMn4 trigonal bipyramids, corners with three equivalent O(5)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, edges with two equivalent O(8)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(8)MgMn4 trigonal bipyramids, corners with three equivalent O(4)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(8)MgMn4 trigonal bipyramid, edges with two equivalent O(1)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(1), one Mn(1), one Mn(2), and one Mn(5) atom to form OMgMn3 trigonal pyramids that share  a cornercorner with one O(1)MgMn4 trigonal bipyramid,  a cornercorner with one O(4)MgMn4 trigonal bipyramid,  a cornercorner with one O(5)MgMn4 trigonal bipyramid,  a cornercorner with one O(8)MgMn4 trigonal bipyramid, corners with three equivalent O(3)Mn4 trigonal pyramids,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(4)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, and  an edgeedge with one O(8)MgMn4 trigonal bipyramid. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Mn(5) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Mn(5) atom to form OMgMn4 trigonal bipyramids that share corners with two equivalent O(5)MgMn4 trigonal bipyramids, corners with three equivalent O(1)MgMn4 trigonal bipyramids,  a cornercorner with one O(6)MgMn3 trigonal pyramid,  a cornercorner with one O(3)Mn4 trigonal pyramid,  an edgeedge with one O(1)MgMn4 trigonal bipyramid,  an edgeedge with one O(5)MgMn4 trigonal bipyramid, edges with two equivalent O(4)MgMn4 trigonal bipyramids,  an edgeedge with one O(6)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn4 trigonal pyramid. is represented by the CIF file [CIF]
data_MgMn5O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.855
_cell_length_b   7.883
_cell_length_c   6.806
_cell_angle_alpha   89.707
_cell_angle_beta   50.855
_cell_angle_gamma   50.656
_symmetry_Int_Tables_number   1
_cell_volume   165.958
_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  0.821  0.968  0.719  1.0
  Mn  Mn1  1  0.993  0.513  0.484  1.0
  Mn  Mn2  1  0.705  0.302  0.283  1.0
  Mn  Mn3  1  0.279  0.995  0.230  1.0
  Mn  Mn4  1  0.034  0.492  0.982  1.0
  Mn  Mn5  1  0.491  0.513  0.981  1.0
  O  O6  1  0.606  0.277  0.656  1.0
  O  O7  1  0.102  0.238  0.553  1.0
  O  O8  1  0.365  0.809  0.943  1.0
  O  O9  1  0.967  0.671  0.789  1.0
  O  O10  1  0.135  0.272  0.132  1.0
  O  O11  1  0.614  0.241  0.069  1.0
  O  O12  1  0.905  0.769  0.402  1.0
  O  O13  1  0.472  0.689  0.278  1.0
[/CIF]
.