The material structure described by Na4C2O5 crystallizes in the monoclinic Cm space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a square pyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(1) atoms. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one C(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one Na(4) and two equivalent O(1) atoms. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Na(1), one Na(4), two equivalent Na(3), and one C(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Na(4), two equivalent Na(2), and one C(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one C(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4C2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.065
_cell_length_b   5.065
_cell_length_c   6.203
_cell_angle_alpha   81.193
_cell_angle_beta   81.193
_cell_angle_gamma   63.784
_symmetry_Int_Tables_number   1
_cell_volume   140.414
_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  0.004  0.004  0.009  1.0
  Na  Na1  1  0.335  0.335  0.735  1.0
  Na  Na2  1  0.668  0.668  0.268  1.0
  Na  Na3  1  0.999  0.999  0.504  1.0
  C  C4  1  0.317  0.317  0.248  1.0
  C  C5  1  0.662  0.662  0.761  1.0
  O  O6  1  0.598  0.183  0.282  1.0
  O  O7  1  0.183  0.598  0.282  1.0
  O  O8  1  0.808  0.387  0.718  1.0
  O  O9  1  0.387  0.808  0.718  1.0
  O  O10  1  0.789  0.789  0.845  1.0
[/CIF]
.
The material structure described by Na4C2O5 crystallizes in the monoclinic Cm space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a square pyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(1) atoms. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one C(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one Na(4) and two equivalent O(1) atoms. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Na(1), one Na(4), two equivalent Na(3), and one C(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Na(4), two equivalent Na(2), and one C(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one C(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4C2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.065
_cell_length_b   5.065
_cell_length_c   6.203
_cell_angle_alpha   81.193
_cell_angle_beta   81.193
_cell_angle_gamma   63.784
_symmetry_Int_Tables_number   1
_cell_volume   140.414
_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  0.004  0.004  0.009  1.0
  Na  Na1  1  0.335  0.335  0.735  1.0
  Na  Na2  1  0.668  0.668  0.268  1.0
  Na  Na3  1  0.999  0.999  0.504  1.0
  C  C4  1  0.317  0.317  0.248  1.0
  C  C5  1  0.662  0.662  0.761  1.0
  O  O6  1  0.598  0.183  0.282  1.0
  O  O7  1  0.183  0.598  0.282  1.0
  O  O8  1  0.808  0.387  0.718  1.0
  O  O9  1  0.387  0.808  0.718  1.0
  O  O10  1  0.789  0.789  0.845  1.0
[/CIF]
.