The structure described by Mg2Sb3O8 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra, corners with three equivalent Mg(2)O4 trigonal pyramids, and edges with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. In the second Mg site, Mg(2) is bonded to one O(4) and three equivalent O(2) atoms to form MgO4 trigonal pyramids that share corners with three equivalent Mg(1)O6 octahedra and corners with nine equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-66°. Sb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O4 trigonal pyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and two equivalent Sb(1) atoms to form distorted OMg2Sb2 tetrahedra that share corners with two equivalent O(2)Mg2Sb2 tetrahedra,  a cornercorner with one O(4)MgSb3 trigonal pyramid, edges with two equivalent O(2)Mg2Sb2 tetrahedra, and  an edgeedge with one O(4)MgSb3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded to one Mg(2) and three equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing OMgSb3 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2Sb3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.535
_cell_length_b   6.535
_cell_length_c   9.625
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   355.988
_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  0.667  0.333  0.029  1.0
  Mg  Mg1  1  0.333  0.667  0.529  1.0
  Mg  Mg2  1  0.667  0.333  0.405  1.0
  Mg  Mg3  1  0.333  0.667  0.905  1.0
  Sb  Sb4  1  0.670  0.835  0.242  1.0
  Sb  Sb5  1  0.835  0.165  0.742  1.0
  Sb  Sb6  1  0.165  0.330  0.242  1.0
  Sb  Sb7  1  0.835  0.670  0.742  1.0
  Sb  Sb8  1  0.330  0.165  0.742  1.0
  Sb  Sb9  1  0.165  0.835  0.242  1.0
  O  O10  1  0.830  0.170  0.146  1.0
  O  O11  1  0.661  0.830  0.646  1.0
  O  O12  1  0.170  0.339  0.646  1.0
  O  O13  1  0.830  0.661  0.146  1.0
  O  O14  1  0.339  0.170  0.146  1.0
  O  O15  1  0.170  0.830  0.646  1.0
  O  O16  1  0.518  0.482  0.876  1.0
  O  O17  1  0.035  0.518  0.376  1.0
  O  O18  1  0.482  0.965  0.376  1.0
  O  O19  1  0.518  0.035  0.876  1.0
  O  O20  1  0.000  0.000  0.348  1.0
  O  O21  1  0.000  0.000  0.848  1.0
  O  O22  1  0.333  0.667  0.117  1.0
  O  O23  1  0.965  0.482  0.876  1.0
  O  O24  1  0.482  0.518  0.376  1.0
  O  O25  1  0.667  0.333  0.617  1.0
[/CIF]
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The structure described by Mg2Sb3O8 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra, corners with three equivalent Mg(2)O4 trigonal pyramids, and edges with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. In the second Mg site, Mg(2) is bonded to one O(4) and three equivalent O(2) atoms to form MgO4 trigonal pyramids that share corners with three equivalent Mg(1)O6 octahedra and corners with nine equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-66°. Sb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O4 trigonal pyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and two equivalent Sb(1) atoms to form distorted OMg2Sb2 tetrahedra that share corners with two equivalent O(2)Mg2Sb2 tetrahedra,  a cornercorner with one O(4)MgSb3 trigonal pyramid, edges with two equivalent O(2)Mg2Sb2 tetrahedra, and  an edgeedge with one O(4)MgSb3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded to one Mg(2) and three equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing OMgSb3 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2Sb3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.535
_cell_length_b   6.535
_cell_length_c   9.625
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   355.988
_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  0.667  0.333  0.029  1.0
  Mg  Mg1  1  0.333  0.667  0.529  1.0
  Mg  Mg2  1  0.667  0.333  0.405  1.0
  Mg  Mg3  1  0.333  0.667  0.905  1.0
  Sb  Sb4  1  0.670  0.835  0.242  1.0
  Sb  Sb5  1  0.835  0.165  0.742  1.0
  Sb  Sb6  1  0.165  0.330  0.242  1.0
  Sb  Sb7  1  0.835  0.670  0.742  1.0
  Sb  Sb8  1  0.330  0.165  0.742  1.0
  Sb  Sb9  1  0.165  0.835  0.242  1.0
  O  O10  1  0.830  0.170  0.146  1.0
  O  O11  1  0.661  0.830  0.646  1.0
  O  O12  1  0.170  0.339  0.646  1.0
  O  O13  1  0.830  0.661  0.146  1.0
  O  O14  1  0.339  0.170  0.146  1.0
  O  O15  1  0.170  0.830  0.646  1.0
  O  O16  1  0.518  0.482  0.876  1.0
  O  O17  1  0.035  0.518  0.376  1.0
  O  O18  1  0.482  0.965  0.376  1.0
  O  O19  1  0.518  0.035  0.876  1.0
  O  O20  1  0.000  0.000  0.348  1.0
  O  O21  1  0.000  0.000  0.848  1.0
  O  O22  1  0.333  0.667  0.117  1.0
  O  O23  1  0.965  0.482  0.876  1.0
  O  O24  1  0.482  0.518  0.376  1.0
  O  O25  1  0.667  0.333  0.617  1.0
[/CIF]
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