The structure described by MgCO3 crystallizes in the orthorhombic C222_1 space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. C(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing CO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to three equivalent Mg(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Mg(1) and two equivalent C(1) atoms. is represented by the CIF card [CIF]
data_MgCO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.163
_cell_length_b   5.163
_cell_length_c   3.647
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   110.973
_symmetry_Int_Tables_number   1
_cell_volume   90.767
_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  0.212  0.788  0.750  1.0
  Mg  Mg1  1  0.788  0.212  0.250  1.0
  C  C2  1  0.653  0.653  0.000  1.0
  C  C3  1  0.347  0.347  0.500  1.0
  O  O4  1  0.654  0.893  0.853  1.0
  O  O5  1  0.417  0.583  0.250  1.0
  O  O6  1  0.346  0.107  0.353  1.0
  O  O7  1  0.107  0.346  0.647  1.0
  O  O8  1  0.583  0.417  0.750  1.0
  O  O9  1  0.893  0.654  0.147  1.0
[/CIF]
.
The structure described by MgCO3 crystallizes in the orthorhombic C222_1 space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. C(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing CO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to three equivalent Mg(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Mg(1) and two equivalent C(1) atoms. is represented by the CIF card [CIF]
data_MgCO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.163
_cell_length_b   5.163
_cell_length_c   3.647
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   110.973
_symmetry_Int_Tables_number   1
_cell_volume   90.767
_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  0.212  0.788  0.750  1.0
  Mg  Mg1  1  0.788  0.212  0.250  1.0
  C  C2  1  0.653  0.653  0.000  1.0
  C  C3  1  0.347  0.347  0.500  1.0
  O  O4  1  0.654  0.893  0.853  1.0
  O  O5  1  0.417  0.583  0.250  1.0
  O  O6  1  0.346  0.107  0.353  1.0
  O  O7  1  0.107  0.346  0.647  1.0
  O  O8  1  0.583  0.417  0.750  1.0
  O  O9  1  0.893  0.654  0.147  1.0
[/CIF]
.