The compound described by Na4MgCr2O8 crystallizes in the monoclinic Pm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(3), one O(5), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), two equivalent O(1), and two equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Mg(1) is bonded in a 5-coordinate geometry to one O(6), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a tetrahedral geometry to one O(3), one O(5), and two equivalent O(2) atoms. In the second Cr site, Cr(2) is bonded in a tetrahedral geometry to one O(4), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Mg(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Mg(1), and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Na(3), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(2), two equivalent Na(3), and one Cr(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Na(1), two equivalent Na(3), and one Cr(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(3), one Mg(1), and one Cr(2) atom. is represented by the CIF file [CIF]
data_Na4MgCr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.058
_cell_length_b   5.911
_cell_length_c   6.578
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   115.375
_symmetry_Int_Tables_number   1
_cell_volume   212.840
_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  0.178  0.835  0.750  1.0
  Na  Na1  1  0.591  0.991  0.250  1.0
  Na  Na2  1  0.549  0.499  0.507  1.0
  Na  Na3  1  0.549  0.499  0.993  1.0
  Mg  Mg4  1  0.097  0.444  0.250  1.0
  Cr  Cr5  1  0.900  0.159  0.750  1.0
  Cr  Cr6  1  0.107  0.893  0.250  1.0
  O  O7  1  0.222  0.744  0.060  1.0
  O  O8  1  0.817  0.261  0.535  1.0
  O  O9  1  0.817  0.261  0.965  1.0
  O  O10  1  0.222  0.744  0.440  1.0
  O  O11  1  0.202  0.259  0.750  1.0
  O  O12  1  0.788  0.748  0.250  1.0
  O  O13  1  0.772  0.847  0.750  1.0
  O  O14  1  0.272  0.234  0.250  1.0
[/CIF]
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The compound described by Na4MgCr2O8 crystallizes in the monoclinic Pm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(3), one O(5), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), two equivalent O(1), and two equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Mg(1) is bonded in a 5-coordinate geometry to one O(6), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a tetrahedral geometry to one O(3), one O(5), and two equivalent O(2) atoms. In the second Cr site, Cr(2) is bonded in a tetrahedral geometry to one O(4), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Mg(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Mg(1), and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Na(3), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(2), two equivalent Na(3), and one Cr(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Na(1), two equivalent Na(3), and one Cr(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(3), one Mg(1), and one Cr(2) atom. is represented by the CIF file [CIF]
data_Na4MgCr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.058
_cell_length_b   5.911
_cell_length_c   6.578
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   115.375
_symmetry_Int_Tables_number   1
_cell_volume   212.840
_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  0.178  0.835  0.750  1.0
  Na  Na1  1  0.591  0.991  0.250  1.0
  Na  Na2  1  0.549  0.499  0.507  1.0
  Na  Na3  1  0.549  0.499  0.993  1.0
  Mg  Mg4  1  0.097  0.444  0.250  1.0
  Cr  Cr5  1  0.900  0.159  0.750  1.0
  Cr  Cr6  1  0.107  0.893  0.250  1.0
  O  O7  1  0.222  0.744  0.060  1.0
  O  O8  1  0.817  0.261  0.535  1.0
  O  O9  1  0.817  0.261  0.965  1.0
  O  O10  1  0.222  0.744  0.440  1.0
  O  O11  1  0.202  0.259  0.750  1.0
  O  O12  1  0.788  0.748  0.250  1.0
  O  O13  1  0.772  0.847  0.750  1.0
  O  O14  1  0.272  0.234  0.250  1.0
[/CIF]
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