The structure described by SrMg6CO8 crystallizes in the tetragonal P4/mmm space group. Sr(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form SrO6 octahedra that share corners with four equivalent Sr(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Sr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Sr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. C(1) is bonded in a linear geometry to two equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Mg(3), and one C(1) atom to form OSrMg4C octahedra that share corners with six equivalent O(1)SrMg4C octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(3)Sr2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Sr2Mg4 octahedra, and edges with four equivalent O(1)SrMg4C octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OSr2Mg4 octahedra that share corners with four equivalent O(3)Sr2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Sr2Mg4 octahedra, and edges with four equivalent O(1)SrMg4C octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded in a square co-planar geometry to two equivalent Mg(2) and two equivalent Mg(3) atoms. is represented by the CIF file [CIF]
data_SrMg6CO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.653
_cell_length_b   4.465
_cell_length_c   4.465
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.514
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.500  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.264  0.000  0.500  1.0
  Mg  Mg4  1  0.736  0.000  0.500  1.0
  Mg  Mg5  1  0.264  0.500  0.000  1.0
  Mg  Mg6  1  0.736  0.500  0.000  1.0
  C  C7  1  0.500  0.000  0.000  1.0
  O  O8  1  0.275  0.000  0.000  1.0
  O  O9  1  0.725  0.000  0.000  1.0
  O  O10  1  0.253  0.500  0.500  1.0
  O  O11  1  0.747  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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The structure described by SrMg6CO8 crystallizes in the tetragonal P4/mmm space group. Sr(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form SrO6 octahedra that share corners with four equivalent Sr(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Sr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Sr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. C(1) is bonded in a linear geometry to two equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Mg(3), and one C(1) atom to form OSrMg4C octahedra that share corners with six equivalent O(1)SrMg4C octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(3)Sr2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Sr2Mg4 octahedra, and edges with four equivalent O(1)SrMg4C octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OSr2Mg4 octahedra that share corners with four equivalent O(3)Sr2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Sr2Mg4 octahedra, and edges with four equivalent O(1)SrMg4C octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded in a square co-planar geometry to two equivalent Mg(2) and two equivalent Mg(3) atoms. is represented by the CIF file [CIF]
data_SrMg6CO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.653
_cell_length_b   4.465
_cell_length_c   4.465
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.514
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.500  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.264  0.000  0.500  1.0
  Mg  Mg4  1  0.736  0.000  0.500  1.0
  Mg  Mg5  1  0.264  0.500  0.000  1.0
  Mg  Mg6  1  0.736  0.500  0.000  1.0
  C  C7  1  0.500  0.000  0.000  1.0
  O  O8  1  0.275  0.000  0.000  1.0
  O  O9  1  0.725  0.000  0.000  1.0
  O  O10  1  0.253  0.500  0.500  1.0
  O  O11  1  0.747  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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