The crystal structure described by Mg5(C2O9)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(6), one O(8), one O(9), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 54-66°. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), one O(6), one O(9), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 53-66°. In the third Mg site, Mg(3) is bonded to two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms to form corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3), one O(5), and one O(7) atom. There are nine inequivalent O sites. In the first O site, O(5) is bonded in a bent 150 degrees geometry to one Mg(3) and one C(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), and one C(1) atom. In the third O site, O(7) is bonded in a bent 150 degrees geometry to one Mg(3) and one C(2) atom. In the fourth O site, O(8) is bonded in a single-bond geometry to one Mg(1) atom. In the fifth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one C(1) atom. In the sixth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one Mg(3) atom. In the seventh O site, O(2) is bonded in a single-bond geometry to one Mg(2) atom. In the eighth O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one C(2) atom. In the ninth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(2) and one C(1) atom. is represented by the CIF file [CIF]
data_Mg5(C2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.168
_cell_length_b   8.404
_cell_length_c   10.080
_cell_angle_alpha   65.844
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   708.556
_cell_formula_units_Z   2
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  0.435  0.491  0.151  1.0
  Mg  Mg1  1  0.565  0.509  0.849  1.0
  Mg  Mg2  1  0.935  0.009  0.849  1.0
  Mg  Mg3  1  0.065  0.991  0.151  1.0
  Mg  Mg4  1  0.068  0.358  0.152  1.0
  Mg  Mg5  1  0.932  0.642  0.848  1.0
  Mg  Mg6  1  0.568  0.142  0.848  1.0
  Mg  Mg7  1  0.432  0.858  0.152  1.0
  Mg  Mg8  1  0.500  0.500  0.500  1.0
  Mg  Mg9  1  0.000  0.000  0.500  1.0
  C  C10  1  0.332  0.237  0.023  1.0
  C  C11  1  0.668  0.763  0.977  1.0
  C  C12  1  0.832  0.263  0.977  1.0
  C  C13  1  0.168  0.737  0.023  1.0
  C  C14  1  0.267  0.270  0.416  1.0
  C  C15  1  0.733  0.730  0.584  1.0
  C  C16  1  0.767  0.230  0.584  1.0
  C  C17  1  0.233  0.770  0.416  1.0
  O  O18  1  0.400  0.381  0.003  1.0
  O  O19  1  0.600  0.619  0.997  1.0
  O  O20  1  0.900  0.119  0.997  1.0
  O  O21  1  0.100  0.881  0.003  1.0
  O  O22  1  0.921  0.450  0.274  1.0
  O  O23  1  0.079  0.550  0.726  1.0
  O  O24  1  0.421  0.050  0.726  1.0
  O  O25  1  0.579  0.950  0.274  1.0
  O  O26  1  0.256  0.362  0.276  1.0
  O  O27  1  0.744  0.638  0.724  1.0
  O  O28  1  0.756  0.138  0.724  1.0
  O  O29  1  0.244  0.862  0.276  1.0
  O  O30  1  0.400  0.114  0.003  1.0
  O  O31  1  0.600  0.886  0.997  1.0
  O  O32  1  0.900  0.386  0.997  1.0
  O  O33  1  0.100  0.614  0.003  1.0
  O  O34  1  0.173  0.155  0.485  1.0
  O  O35  1  0.827  0.845  0.515  1.0
  O  O36  1  0.673  0.345  0.515  1.0
  O  O37  1  0.327  0.655  0.485  1.0
  O  O38  1  0.198  0.217  0.065  1.0
  O  O39  1  0.802  0.783  0.935  1.0
  O  O40  1  0.698  0.283  0.935  1.0
  O  O41  1  0.302  0.717  0.065  1.0
  O  O42  1  0.376  0.296  0.485  1.0
  O  O43  1  0.624  0.704  0.515  1.0
  O  O44  1  0.876  0.204  0.515  1.0
  O  O45  1  0.124  0.796  0.485  1.0
  O  O46  1  0.112  0.188  0.748  1.0
  O  O47  1  0.888  0.812  0.252  1.0
  O  O48  1  0.612  0.312  0.252  1.0
  O  O49  1  0.388  0.688  0.748  1.0
  O  O50  1  0.002  0.110  0.282  1.0
  O  O51  1  0.998  0.890  0.718  1.0
  O  O52  1  0.502  0.390  0.718  1.0
  O  O53  1  0.498  0.610  0.282  1.0
[/CIF]
.
The crystal structure described by Mg5(C2O9)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(6), one O(8), one O(9), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 54-66°. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), one O(6), one O(9), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 53-66°. In the third Mg site, Mg(3) is bonded to two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms to form corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3), one O(5), and one O(7) atom. There are nine inequivalent O sites. In the first O site, O(5) is bonded in a bent 150 degrees geometry to one Mg(3) and one C(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), and one C(1) atom. In the third O site, O(7) is bonded in a bent 150 degrees geometry to one Mg(3) and one C(2) atom. In the fourth O site, O(8) is bonded in a single-bond geometry to one Mg(1) atom. In the fifth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one C(1) atom. In the sixth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one Mg(3) atom. In the seventh O site, O(2) is bonded in a single-bond geometry to one Mg(2) atom. In the eighth O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one C(2) atom. In the ninth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(2) and one C(1) atom. is represented by the CIF file [CIF]
data_Mg5(C2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.168
_cell_length_b   8.404
_cell_length_c   10.080
_cell_angle_alpha   65.844
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   708.556
_cell_formula_units_Z   2
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  0.435  0.491  0.151  1.0
  Mg  Mg1  1  0.565  0.509  0.849  1.0
  Mg  Mg2  1  0.935  0.009  0.849  1.0
  Mg  Mg3  1  0.065  0.991  0.151  1.0
  Mg  Mg4  1  0.068  0.358  0.152  1.0
  Mg  Mg5  1  0.932  0.642  0.848  1.0
  Mg  Mg6  1  0.568  0.142  0.848  1.0
  Mg  Mg7  1  0.432  0.858  0.152  1.0
  Mg  Mg8  1  0.500  0.500  0.500  1.0
  Mg  Mg9  1  0.000  0.000  0.500  1.0
  C  C10  1  0.332  0.237  0.023  1.0
  C  C11  1  0.668  0.763  0.977  1.0
  C  C12  1  0.832  0.263  0.977  1.0
  C  C13  1  0.168  0.737  0.023  1.0
  C  C14  1  0.267  0.270  0.416  1.0
  C  C15  1  0.733  0.730  0.584  1.0
  C  C16  1  0.767  0.230  0.584  1.0
  C  C17  1  0.233  0.770  0.416  1.0
  O  O18  1  0.400  0.381  0.003  1.0
  O  O19  1  0.600  0.619  0.997  1.0
  O  O20  1  0.900  0.119  0.997  1.0
  O  O21  1  0.100  0.881  0.003  1.0
  O  O22  1  0.921  0.450  0.274  1.0
  O  O23  1  0.079  0.550  0.726  1.0
  O  O24  1  0.421  0.050  0.726  1.0
  O  O25  1  0.579  0.950  0.274  1.0
  O  O26  1  0.256  0.362  0.276  1.0
  O  O27  1  0.744  0.638  0.724  1.0
  O  O28  1  0.756  0.138  0.724  1.0
  O  O29  1  0.244  0.862  0.276  1.0
  O  O30  1  0.400  0.114  0.003  1.0
  O  O31  1  0.600  0.886  0.997  1.0
  O  O32  1  0.900  0.386  0.997  1.0
  O  O33  1  0.100  0.614  0.003  1.0
  O  O34  1  0.173  0.155  0.485  1.0
  O  O35  1  0.827  0.845  0.515  1.0
  O  O36  1  0.673  0.345  0.515  1.0
  O  O37  1  0.327  0.655  0.485  1.0
  O  O38  1  0.198  0.217  0.065  1.0
  O  O39  1  0.802  0.783  0.935  1.0
  O  O40  1  0.698  0.283  0.935  1.0
  O  O41  1  0.302  0.717  0.065  1.0
  O  O42  1  0.376  0.296  0.485  1.0
  O  O43  1  0.624  0.704  0.515  1.0
  O  O44  1  0.876  0.204  0.515  1.0
  O  O45  1  0.124  0.796  0.485  1.0
  O  O46  1  0.112  0.188  0.748  1.0
  O  O47  1  0.888  0.812  0.252  1.0
  O  O48  1  0.612  0.312  0.252  1.0
  O  O49  1  0.388  0.688  0.748  1.0
  O  O50  1  0.002  0.110  0.282  1.0
  O  O51  1  0.998  0.890  0.718  1.0
  O  O52  1  0.502  0.390  0.718  1.0
  O  O53  1  0.498  0.610  0.282  1.0
[/CIF]
.