The crystal structure described by Mg6NbBiO8 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)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 MgO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Mg(2)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. 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 Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Bi(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Nb(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, edges with four equivalent Bi(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Bi(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Bi(1)O6 octahedra, edges with four equivalent Nb(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), four equivalent Mg(3), and one Nb(1) atom to form OMg5Nb octahedra that share corners with six equivalent O(1)Mg5Nb octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Mg(2), four equivalent Mg(3), and one Bi(1) atom to form OMg5Bi octahedra that share corners with six equivalent O(2)Mg5Bi octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(1)Mg5Nb octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the third O site, O(3) is bonded to two equivalent Mg(3), two equivalent Nb(1), and two equivalent Bi(1) atoms to form OMg2Nb2Bi2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, and edges with four equivalent O(1)Mg5Nb octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg2Nb2Bi2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, edges with four equivalent O(1)Mg5Nb octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6NbBiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.866
_cell_length_b   4.542
_cell_length_c   4.542
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.921
_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
  Mg  Mg0  1  0.500  0.000  0.000  1.0
  Mg  Mg1  1  0.500  0.500  0.500  1.0
  Mg  Mg2  1  0.269  0.000  0.500  1.0
  Mg  Mg3  1  0.731  0.000  0.500  1.0
  Mg  Mg4  1  0.269  0.500  0.000  1.0
  Mg  Mg5  1  0.731  0.500  0.000  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Bi  Bi7  1  0.000  0.500  0.500  1.0
  O  O8  1  0.266  0.000  0.000  1.0
  O  O9  1  0.734  0.000  0.000  1.0
  O  O10  1  0.278  0.500  0.500  1.0
  O  O11  1  0.722  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 crystal structure described by Mg6NbBiO8 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)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 MgO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Mg(2)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. 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 Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Bi(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Nb(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, edges with four equivalent Bi(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. Bi(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Bi(1)O6 octahedra, edges with four equivalent Nb(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), four equivalent Mg(3), and one Nb(1) atom to form OMg5Nb octahedra that share corners with six equivalent O(1)Mg5Nb octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Mg(2), four equivalent Mg(3), and one Bi(1) atom to form OMg5Bi octahedra that share corners with six equivalent O(2)Mg5Bi octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(1)Mg5Nb octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the third O site, O(3) is bonded to two equivalent Mg(3), two equivalent Nb(1), and two equivalent Bi(1) atoms to form OMg2Nb2Bi2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(3)Mg2Nb2Bi2 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, and edges with four equivalent O(1)Mg5Nb octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg2Nb2Bi2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(2)Mg5Bi octahedra, edges with four equivalent O(1)Mg5Nb octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6NbBiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.866
_cell_length_b   4.542
_cell_length_c   4.542
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.921
_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
  Mg  Mg0  1  0.500  0.000  0.000  1.0
  Mg  Mg1  1  0.500  0.500  0.500  1.0
  Mg  Mg2  1  0.269  0.000  0.500  1.0
  Mg  Mg3  1  0.731  0.000  0.500  1.0
  Mg  Mg4  1  0.269  0.500  0.000  1.0
  Mg  Mg5  1  0.731  0.500  0.000  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Bi  Bi7  1  0.000  0.500  0.500  1.0
  O  O8  1  0.266  0.000  0.000  1.0
  O  O9  1  0.734  0.000  0.000  1.0
  O  O10  1  0.278  0.500  0.500  1.0
  O  O11  1  0.722  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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