The structure described by Na2MgMn4O8 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(5), one O(8), and two equivalent O(4) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Mn(3)O5 square pyramid, corners with two equivalent Na(1)O5 square pyramids, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Mn(4)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(6), one O(8), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to one O(1), one O(7), and two equivalent O(6) atoms to form MgO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(3)O5 square pyramids, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-55°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form MnO6 octahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Na(1)O5 square pyramids, and edges with two equivalent Mn(4)O5 trigonal bipyramids. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(4), one O(7), two equivalent O(3), and two equivalent O(5) atoms. In the third Mn site, Mn(3) is bonded to one O(3), two equivalent O(1), and two equivalent O(7) atoms to form distorted MnO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid, corners with four equivalent Mg(1)O4 tetrahedra, and edges with two equivalent Mn(3)O5 square pyramids. In the fourth Mn site, Mn(4) is bonded to one O(2), one O(5), one O(8), and two equivalent O(4) atoms to form MnO5 trigonal bipyramids that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Na(1)O5 square pyramids, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Na(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 26-65°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(2), one Mg(1), and two equivalent Mn(3) atoms. In the second O site, O(2) is bonded to two equivalent Na(2), one Mn(4), and two equivalent Mn(1) atoms to form distorted ONa2Mn3 square pyramids that share  a cornercorner with one O(5)NaMn3 tetrahedra, corners with three equivalent O(8)Na2Mn3 trigonal bipyramids, corners with four equivalent O(6)NaMg2Mn trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids, and edges with two equivalent O(8)Na2Mn3 trigonal bipyramids. In the third O site, O(3) is bonded to one Na(1), one Mn(3), and two equivalent Mn(2) atoms to form ONaMn3 trigonal pyramids that share corners with three equivalent O(5)NaMn3 tetrahedra, corners with four equivalent O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)Na2Mn3 trigonal bipyramid, corners with two equivalent O(3)NaMn3 trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra, and  an edgeedge with one O(5)NaMn3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Na(1), one Mn(1), one Mn(2), and two equivalent Mn(4) atoms to form distorted ONa2Mn4 octahedra that share  a cornercorner with one O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with two equivalent O(8)Na2Mn3 trigonal bipyramids,  a cornercorner with one O(6)NaMg2Mn trigonal pyramid, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids, edges with two equivalent O(5)NaMn3 tetrahedra, edges with two equivalent O(8)Na2Mn3 trigonal bipyramids, and edges with two equivalent O(3)NaMn3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Mn(4), and two equivalent Mn(2) atoms to form ONaMn3 tetrahedra that share corners with two equivalent O(4)Na2Mn4 octahedra,  a cornercorner with one O(2)Na2Mn3 square pyramid, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with three equivalent O(3)NaMn3 trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra,  an edgeedge with one O(8)Na2Mn3 trigonal bipyramid, and  an edgeedge with one O(3)NaMn3 trigonal pyramid. The corner-sharing octahedral tilt angles range from 39-55°. In the sixth O site, O(6) is bonded to one Na(2), two equivalent Mg(1), and one Mn(1) atom to form ONaMg2Mn trigonal pyramids that share  a cornercorner with one O(4)Na2Mn4 octahedra, corners with four equivalent O(2)Na2Mn3 square pyramids, corners with two equivalent O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)Na2Mn3 trigonal bipyramid, corners with two equivalent O(6)NaMg2Mn trigonal pyramids, and  an edgeedge with one O(8)Na2Mn3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 17°. In the seventh O site, O(7) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form OMgMn3 tetrahedra that share  a cornercorner with one O(4)Na2Mn4 octahedra, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with two equivalent O(6)NaMg2Mn trigonal pyramids, and corners with four equivalent O(3)NaMn3 trigonal pyramids. The corner-sharing octahedral tilt angles are 18°. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Mn(4), and two equivalent Mn(1) atoms to form distorted ONa2Mn3 trigonal bipyramids that share corners with two equivalent O(4)Na2Mn4 octahedra, corners with three equivalent O(2)Na2Mn3 square pyramids, corners with two equivalent O(8)Na2Mn3 trigonal bipyramids,  a cornercorner with one O(6)NaMg2Mn trigonal pyramid,  a cornercorner with one O(3)NaMn3 trigonal pyramid, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids,  an edgeedge with one O(5)NaMn3 tetrahedra, and  an edgeedge with one O(6)NaMg2Mn trigonal pyramid. The corner-sharing octahedral tilt angles range from 30-66°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2MgMn4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.063
_cell_length_b   6.126
_cell_length_c   11.061
_cell_angle_alpha   82.802
_cell_angle_beta   98.747
_cell_angle_gamma   61.275
_symmetry_Int_Tables_number   1
_cell_volume   175.106
_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
  Na  Na0  1  0.224  0.250  0.210  1.0
  Na  Na1  1  0.790  0.869  0.810  1.0
  Mg  Mg2  1  0.591  0.551  0.657  1.0
  Mn  Mn3  1  0.519  0.302  0.945  1.0
  Mn  Mn4  1  0.222  0.748  0.339  1.0
  Mn  Mn5  1  0.431  0.143  0.537  1.0
  Mn  Mn6  1  0.502  0.814  0.074  1.0
  O  O7  1  0.178  0.937  0.623  1.0
  O  O8  1  0.165  0.052  0.916  1.0
  O  O9  1  0.576  0.930  0.396  1.0
  O  O10  1  0.865  0.035  0.119  1.0
  O  O11  1  0.794  0.620  0.253  1.0
  O  O12  1  0.237  0.462  0.764  1.0
  O  O13  1  0.662  0.399  0.500  1.0
  O  O14  1  0.911  0.525  0.002  1.0
[/CIF]
.
The structure described by Na2MgMn4O8 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(5), one O(8), and two equivalent O(4) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Mn(3)O5 square pyramid, corners with two equivalent Na(1)O5 square pyramids, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Mn(4)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(6), one O(8), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to one O(1), one O(7), and two equivalent O(6) atoms to form MgO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(3)O5 square pyramids, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-55°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form MnO6 octahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Na(1)O5 square pyramids, and edges with two equivalent Mn(4)O5 trigonal bipyramids. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(4), one O(7), two equivalent O(3), and two equivalent O(5) atoms. In the third Mn site, Mn(3) is bonded to one O(3), two equivalent O(1), and two equivalent O(7) atoms to form distorted MnO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid, corners with four equivalent Mg(1)O4 tetrahedra, and edges with two equivalent Mn(3)O5 square pyramids. In the fourth Mn site, Mn(4) is bonded to one O(2), one O(5), one O(8), and two equivalent O(4) atoms to form MnO5 trigonal bipyramids that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Na(1)O5 square pyramids, corners with two equivalent Mn(4)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Na(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 26-65°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(2), one Mg(1), and two equivalent Mn(3) atoms. In the second O site, O(2) is bonded to two equivalent Na(2), one Mn(4), and two equivalent Mn(1) atoms to form distorted ONa2Mn3 square pyramids that share  a cornercorner with one O(5)NaMn3 tetrahedra, corners with three equivalent O(8)Na2Mn3 trigonal bipyramids, corners with four equivalent O(6)NaMg2Mn trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids, and edges with two equivalent O(8)Na2Mn3 trigonal bipyramids. In the third O site, O(3) is bonded to one Na(1), one Mn(3), and two equivalent Mn(2) atoms to form ONaMn3 trigonal pyramids that share corners with three equivalent O(5)NaMn3 tetrahedra, corners with four equivalent O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)Na2Mn3 trigonal bipyramid, corners with two equivalent O(3)NaMn3 trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra, and  an edgeedge with one O(5)NaMn3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Na(1), one Mn(1), one Mn(2), and two equivalent Mn(4) atoms to form distorted ONa2Mn4 octahedra that share  a cornercorner with one O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with two equivalent O(8)Na2Mn3 trigonal bipyramids,  a cornercorner with one O(6)NaMg2Mn trigonal pyramid, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids, edges with two equivalent O(5)NaMn3 tetrahedra, edges with two equivalent O(8)Na2Mn3 trigonal bipyramids, and edges with two equivalent O(3)NaMn3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Mn(4), and two equivalent Mn(2) atoms to form ONaMn3 tetrahedra that share corners with two equivalent O(4)Na2Mn4 octahedra,  a cornercorner with one O(2)Na2Mn3 square pyramid, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with three equivalent O(3)NaMn3 trigonal pyramids, edges with two equivalent O(4)Na2Mn4 octahedra,  an edgeedge with one O(8)Na2Mn3 trigonal bipyramid, and  an edgeedge with one O(3)NaMn3 trigonal pyramid. The corner-sharing octahedral tilt angles range from 39-55°. In the sixth O site, O(6) is bonded to one Na(2), two equivalent Mg(1), and one Mn(1) atom to form ONaMg2Mn trigonal pyramids that share  a cornercorner with one O(4)Na2Mn4 octahedra, corners with four equivalent O(2)Na2Mn3 square pyramids, corners with two equivalent O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)Na2Mn3 trigonal bipyramid, corners with two equivalent O(6)NaMg2Mn trigonal pyramids, and  an edgeedge with one O(8)Na2Mn3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 17°. In the seventh O site, O(7) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form OMgMn3 tetrahedra that share  a cornercorner with one O(4)Na2Mn4 octahedra, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(5)NaMn3 tetrahedra, corners with two equivalent O(6)NaMg2Mn trigonal pyramids, and corners with four equivalent O(3)NaMn3 trigonal pyramids. The corner-sharing octahedral tilt angles are 18°. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Mn(4), and two equivalent Mn(1) atoms to form distorted ONa2Mn3 trigonal bipyramids that share corners with two equivalent O(4)Na2Mn4 octahedra, corners with three equivalent O(2)Na2Mn3 square pyramids, corners with two equivalent O(8)Na2Mn3 trigonal bipyramids,  a cornercorner with one O(6)NaMg2Mn trigonal pyramid,  a cornercorner with one O(3)NaMn3 trigonal pyramid, edges with two equivalent O(4)Na2Mn4 octahedra, edges with two equivalent O(2)Na2Mn3 square pyramids,  an edgeedge with one O(5)NaMn3 tetrahedra, and  an edgeedge with one O(6)NaMg2Mn trigonal pyramid. The corner-sharing octahedral tilt angles range from 30-66°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2MgMn4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.063
_cell_length_b   6.126
_cell_length_c   11.061
_cell_angle_alpha   82.802
_cell_angle_beta   98.747
_cell_angle_gamma   61.275
_symmetry_Int_Tables_number   1
_cell_volume   175.106
_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
  Na  Na0  1  0.224  0.250  0.210  1.0
  Na  Na1  1  0.790  0.869  0.810  1.0
  Mg  Mg2  1  0.591  0.551  0.657  1.0
  Mn  Mn3  1  0.519  0.302  0.945  1.0
  Mn  Mn4  1  0.222  0.748  0.339  1.0
  Mn  Mn5  1  0.431  0.143  0.537  1.0
  Mn  Mn6  1  0.502  0.814  0.074  1.0
  O  O7  1  0.178  0.937  0.623  1.0
  O  O8  1  0.165  0.052  0.916  1.0
  O  O9  1  0.576  0.930  0.396  1.0
  O  O10  1  0.865  0.035  0.119  1.0
  O  O11  1  0.794  0.620  0.253  1.0
  O  O12  1  0.237  0.462  0.764  1.0
  O  O13  1  0.662  0.399  0.500  1.0
  O  O14  1  0.911  0.525  0.002  1.0
[/CIF]
.