The material structure described by Na8Mg(CoO4)2 crystallizes in the triclinic P1 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(8) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(5), one O(6), and one O(8) atom. In the third Na site, Na(3) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(8)O4 tetrahedra,  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Co(2)O4 tetrahedra, and  an edgeedge with one Na(4)O4 trigonal pyramid. In the fourth Na site, Na(4) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with three equivalent Na(8)O4 tetrahedra, corners with three equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Na(3)O5 square pyramid, and  an edgeedge with one Co(2)O4 tetrahedra. In the fifth Na site, Na(5) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the sixth Na site, Na(6) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and one O(8) atom. In the seventh Na site, Na(7) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and one O(8) atom. In the eighth Na site, Na(8) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(2)O4 tetrahedra, corners with three equivalent Na(4)O4 trigonal pyramids, and  an edgeedge with one Mg(1)O4 tetrahedra. Mg(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with three equivalent Na(4)O4 trigonal pyramids,  an edgeedge with one Na(8)O4 tetrahedra, and  an edgeedge with one Co(2)O4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(6), one O(7), and one O(8) atom to form CoO4 tetrahedra that share corners with two equivalent Na(3)O5 square pyramids, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  a cornercorner with one Na(4)O4 trigonal pyramid. In the second Co site, Co(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted CoO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Na(8)O4 tetrahedra,  a cornercorner with one Na(4)O4 trigonal pyramid,  an edgeedge with one Na(3)O5 square pyramid,  an edgeedge with one Mg(1)O4 tetrahedra, and  an edgeedge with one Na(4)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Na(7), and one Co(1) atom to form ONa5Co octahedra that share corners with two equivalent O(8)Na5Co octahedra, edges with two equivalent O(2)Na5Co octahedra, edges with two equivalent O(8)Na5Co octahedra, and edges with two equivalent O(6)Na4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 10-19°. In the second O site, O(2) is bonded to one Na(1), one Na(3), one Na(5), one Na(6), one Na(7), and one Co(2) atom to form ONa5Co octahedra that share corners with two equivalent O(6)Na4MgCo pentagonal pyramids, edges with two equivalent O(1)Na5Co octahedra, and edges with two equivalent O(8)Na5Co octahedra. In the third O site, O(3) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(6), one Na(7), and one Co(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(3), one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(2), one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(2) atom. In the sixth O site, O(6) is bonded to one Na(2), one Na(6), one Na(7), one Na(8), one Mg(1), and one Co(1) atom to form a mixture of distorted corner and edge-sharing ONa4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 7-9°. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(1) atom. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Na(7), and one Co(1) atom to form distorted ONa5Co octahedra that share corners with two equivalent O(1)Na5Co octahedra, edges with two equivalent O(1)Na5Co octahedra, edges with two equivalent O(2)Na5Co octahedra, and edges with two equivalent O(6)Na4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 10-19°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na8Mg(CoO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.589
_cell_length_b   5.960
_cell_length_c   9.083
_cell_angle_alpha   68.589
_cell_angle_beta   79.782
_cell_angle_gamma   70.740
_symmetry_Int_Tables_number   1
_cell_volume   265.350
_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  0.967  0.823  0.331  1.0
  Na  Na1  1  0.479  0.508  0.972  1.0
  Na  Na2  1  0.470  0.311  0.331  1.0
  Na  Na3  1  0.297  0.964  0.696  1.0
  Na  Na4  1  0.952  0.291  0.538  1.0
  Na  Na5  1  0.489  0.923  0.141  1.0
  Na  Na6  1  0.994  0.405  0.160  1.0
  Na  Na7  1  0.970  0.606  0.753  1.0
  Mg  Mg8  1  0.520  0.264  0.770  1.0
  Co  Co9  1  0.006  0.030  0.995  1.0
  Co  Co10  1  0.455  0.670  0.488  1.0
  O  O11  1  0.755  0.177  0.124  1.0
  O  O12  1  0.704  0.578  0.346  1.0
  O  O13  1  0.226  0.982  0.428  1.0
  O  O14  1  0.319  0.377  0.578  1.0
  O  O15  1  0.585  0.598  0.696  1.0
  O  O16  1  0.239  0.238  0.938  1.0
  O  O17  1  0.867  0.012  0.816  1.0
  O  O18  1  0.201  0.715  0.112  1.0
[/CIF]
.
The material structure described by Na8Mg(CoO4)2 crystallizes in the triclinic P1 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(8) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(5), one O(6), and one O(8) atom. In the third Na site, Na(3) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(8)O4 tetrahedra,  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Co(2)O4 tetrahedra, and  an edgeedge with one Na(4)O4 trigonal pyramid. In the fourth Na site, Na(4) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with three equivalent Na(8)O4 tetrahedra, corners with three equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Na(3)O5 square pyramid, and  an edgeedge with one Co(2)O4 tetrahedra. In the fifth Na site, Na(5) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the sixth Na site, Na(6) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and one O(8) atom. In the seventh Na site, Na(7) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and one O(8) atom. In the eighth Na site, Na(8) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(2)O4 tetrahedra, corners with three equivalent Na(4)O4 trigonal pyramids, and  an edgeedge with one Mg(1)O4 tetrahedra. Mg(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with three equivalent Na(4)O4 trigonal pyramids,  an edgeedge with one Na(8)O4 tetrahedra, and  an edgeedge with one Co(2)O4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(6), one O(7), and one O(8) atom to form CoO4 tetrahedra that share corners with two equivalent Na(3)O5 square pyramids, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  a cornercorner with one Na(4)O4 trigonal pyramid. In the second Co site, Co(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted CoO4 tetrahedra that share  a cornercorner with one Na(3)O5 square pyramid, corners with two equivalent Na(8)O4 tetrahedra,  a cornercorner with one Na(4)O4 trigonal pyramid,  an edgeedge with one Na(3)O5 square pyramid,  an edgeedge with one Mg(1)O4 tetrahedra, and  an edgeedge with one Na(4)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Na(7), and one Co(1) atom to form ONa5Co octahedra that share corners with two equivalent O(8)Na5Co octahedra, edges with two equivalent O(2)Na5Co octahedra, edges with two equivalent O(8)Na5Co octahedra, and edges with two equivalent O(6)Na4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 10-19°. In the second O site, O(2) is bonded to one Na(1), one Na(3), one Na(5), one Na(6), one Na(7), and one Co(2) atom to form ONa5Co octahedra that share corners with two equivalent O(6)Na4MgCo pentagonal pyramids, edges with two equivalent O(1)Na5Co octahedra, and edges with two equivalent O(8)Na5Co octahedra. In the third O site, O(3) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(6), one Na(7), and one Co(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(3), one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(2), one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(2) atom. In the sixth O site, O(6) is bonded to one Na(2), one Na(6), one Na(7), one Na(8), one Mg(1), and one Co(1) atom to form a mixture of distorted corner and edge-sharing ONa4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 7-9°. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Na(4), one Na(5), one Na(8), one Mg(1), and one Co(1) atom. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Na(7), and one Co(1) atom to form distorted ONa5Co octahedra that share corners with two equivalent O(1)Na5Co octahedra, edges with two equivalent O(1)Na5Co octahedra, edges with two equivalent O(2)Na5Co octahedra, and edges with two equivalent O(6)Na4MgCo pentagonal pyramids. The corner-sharing octahedral tilt angles range from 10-19°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na8Mg(CoO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.589
_cell_length_b   5.960
_cell_length_c   9.083
_cell_angle_alpha   68.589
_cell_angle_beta   79.782
_cell_angle_gamma   70.740
_symmetry_Int_Tables_number   1
_cell_volume   265.350
_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  0.967  0.823  0.331  1.0
  Na  Na1  1  0.479  0.508  0.972  1.0
  Na  Na2  1  0.470  0.311  0.331  1.0
  Na  Na3  1  0.297  0.964  0.696  1.0
  Na  Na4  1  0.952  0.291  0.538  1.0
  Na  Na5  1  0.489  0.923  0.141  1.0
  Na  Na6  1  0.994  0.405  0.160  1.0
  Na  Na7  1  0.970  0.606  0.753  1.0
  Mg  Mg8  1  0.520  0.264  0.770  1.0
  Co  Co9  1  0.006  0.030  0.995  1.0
  Co  Co10  1  0.455  0.670  0.488  1.0
  O  O11  1  0.755  0.177  0.124  1.0
  O  O12  1  0.704  0.578  0.346  1.0
  O  O13  1  0.226  0.982  0.428  1.0
  O  O14  1  0.319  0.377  0.578  1.0
  O  O15  1  0.585  0.598  0.696  1.0
  O  O16  1  0.239  0.238  0.938  1.0
  O  O17  1  0.867  0.012  0.816  1.0
  O  O18  1  0.201  0.715  0.112  1.0
[/CIF]
.