The material described by Mg(CO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the second Mg site, Mg(2) is bonded in a distorted octahedral geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. 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(2), 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(4), and one O(5) atom. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(1) atom. In the second O site, O(1) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the fourth O site, O(3) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one C(2) atom. In the sixth O site, O(5) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. is represented by the CIF file [CIF]
data_Mg(CO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.878
_cell_length_b   7.858
_cell_length_c   9.054
_cell_angle_alpha   80.869
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   553.412
_cell_formula_units_Z   4
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  0.500  0.000  0.500  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  C  C4  1  0.678  0.832  0.821  1.0
  C  C5  1  0.178  0.168  0.679  1.0
  C  C6  1  0.322  0.168  0.179  1.0
  C  C7  1  0.822  0.832  0.321  1.0
  C  C8  1  0.235  0.691  0.985  1.0
  C  C9  1  0.735  0.309  0.515  1.0
  C  C10  1  0.765  0.309  0.015  1.0
  C  C11  1  0.265  0.691  0.485  1.0
  O  O12  1  0.610  0.920  0.706  1.0
  O  O13  1  0.110  0.080  0.794  1.0
  O  O14  1  0.390  0.080  0.294  1.0
  O  O15  1  0.890  0.920  0.206  1.0
  O  O16  1  0.778  0.905  0.902  1.0
  O  O17  1  0.278  0.095  0.598  1.0
  O  O18  1  0.222  0.095  0.098  1.0
  O  O19  1  0.722  0.905  0.402  1.0
  O  O20  1  0.261  0.585  0.892  1.0
  O  O21  1  0.761  0.415  0.608  1.0
  O  O22  1  0.739  0.415  0.108  1.0
  O  O23  1  0.239  0.585  0.392  1.0
  O  O24  1  0.093  0.759  0.004  1.0
  O  O25  1  0.593  0.241  0.496  1.0
  O  O26  1  0.907  0.241  0.996  1.0
  O  O27  1  0.407  0.759  0.504  1.0
  O  O28  1  0.130  0.717  0.560  1.0
  O  O29  1  0.630  0.283  0.940  1.0
  O  O30  1  0.870  0.283  0.440  1.0
  O  O31  1  0.370  0.717  0.060  1.0
  O  O32  1  0.645  0.671  0.856  1.0
  O  O33  1  0.145  0.329  0.644  1.0
  O  O34  1  0.355  0.329  0.144  1.0
  O  O35  1  0.855  0.671  0.356  1.0
[/CIF]
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The material described by Mg(CO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the second Mg site, Mg(2) is bonded in a distorted octahedral geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. 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(2), 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(4), and one O(5) atom. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(1) atom. In the second O site, O(1) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the fourth O site, O(3) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one C(2) atom. In the sixth O site, O(5) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. is represented by the CIF file [CIF]
data_Mg(CO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.878
_cell_length_b   7.858
_cell_length_c   9.054
_cell_angle_alpha   80.869
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   553.412
_cell_formula_units_Z   4
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  0.500  0.000  0.500  1.0
  Mg  Mg1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  C  C4  1  0.678  0.832  0.821  1.0
  C  C5  1  0.178  0.168  0.679  1.0
  C  C6  1  0.322  0.168  0.179  1.0
  C  C7  1  0.822  0.832  0.321  1.0
  C  C8  1  0.235  0.691  0.985  1.0
  C  C9  1  0.735  0.309  0.515  1.0
  C  C10  1  0.765  0.309  0.015  1.0
  C  C11  1  0.265  0.691  0.485  1.0
  O  O12  1  0.610  0.920  0.706  1.0
  O  O13  1  0.110  0.080  0.794  1.0
  O  O14  1  0.390  0.080  0.294  1.0
  O  O15  1  0.890  0.920  0.206  1.0
  O  O16  1  0.778  0.905  0.902  1.0
  O  O17  1  0.278  0.095  0.598  1.0
  O  O18  1  0.222  0.095  0.098  1.0
  O  O19  1  0.722  0.905  0.402  1.0
  O  O20  1  0.261  0.585  0.892  1.0
  O  O21  1  0.761  0.415  0.608  1.0
  O  O22  1  0.739  0.415  0.108  1.0
  O  O23  1  0.239  0.585  0.392  1.0
  O  O24  1  0.093  0.759  0.004  1.0
  O  O25  1  0.593  0.241  0.496  1.0
  O  O26  1  0.907  0.241  0.996  1.0
  O  O27  1  0.407  0.759  0.504  1.0
  O  O28  1  0.130  0.717  0.560  1.0
  O  O29  1  0.630  0.283  0.940  1.0
  O  O30  1  0.870  0.283  0.440  1.0
  O  O31  1  0.370  0.717  0.060  1.0
  O  O32  1  0.645  0.671  0.856  1.0
  O  O33  1  0.145  0.329  0.644  1.0
  O  O34  1  0.355  0.329  0.144  1.0
  O  O35  1  0.855  0.671  0.356  1.0
[/CIF]
.