The crystal structure described by MgAl2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2) and three equivalent O(1) atoms to form MgO4 tetrahedra that share corners with three equivalent Mg(2)O6 octahedra and corners with nine equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-62°. In the second Mg site, Mg(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Al(2)O4 tetrahedra, and edges with six equivalent Al(1)O6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Al(2)O4 tetrahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to one O(3) and three equivalent O(4) atoms to form AlO4 tetrahedra that share corners with three equivalent Mg(2)O6 octahedra and corners with nine equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1) and three equivalent Al(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Al(2) and three equivalent Al(1) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Al(2), and two equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_MgAl2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.787
_cell_length_b   5.787
_cell_length_c   5.787
_cell_angle_alpha   59.556
_cell_angle_beta   59.556
_cell_angle_gamma   59.556
_symmetry_Int_Tables_number   1
_cell_volume   135.689
_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  0.622  0.622  0.622  1.0
  Mg  Mg1  1  0.999  0.999  0.999  1.0
  Al  Al2  1  0.996  0.510  0.996  1.0
  Al  Al3  1  0.996  0.996  0.510  1.0
  Al  Al4  1  0.510  0.996  0.996  1.0
  Al  Al5  1  0.380  0.380  0.380  1.0
  O  O6  1  0.753  0.753  0.212  1.0
  O  O7  1  0.753  0.212  0.753  1.0
  O  O8  1  0.212  0.753  0.753  1.0
  O  O9  1  0.760  0.760  0.760  1.0
  O  O10  1  0.246  0.246  0.246  1.0
  O  O11  1  0.770  0.251  0.251  1.0
  O  O12  1  0.251  0.770  0.251  1.0
  O  O13  1  0.251  0.251  0.770  1.0
[/CIF]
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The crystal structure described by MgAl2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2) and three equivalent O(1) atoms to form MgO4 tetrahedra that share corners with three equivalent Mg(2)O6 octahedra and corners with nine equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-62°. In the second Mg site, Mg(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Al(2)O4 tetrahedra, and edges with six equivalent Al(1)O6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Al(2)O4 tetrahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to one O(3) and three equivalent O(4) atoms to form AlO4 tetrahedra that share corners with three equivalent Mg(2)O6 octahedra and corners with nine equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1) and three equivalent Al(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Al(2) and three equivalent Al(1) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Al(2), and two equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_MgAl2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.787
_cell_length_b   5.787
_cell_length_c   5.787
_cell_angle_alpha   59.556
_cell_angle_beta   59.556
_cell_angle_gamma   59.556
_symmetry_Int_Tables_number   1
_cell_volume   135.689
_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  0.622  0.622  0.622  1.0
  Mg  Mg1  1  0.999  0.999  0.999  1.0
  Al  Al2  1  0.996  0.510  0.996  1.0
  Al  Al3  1  0.996  0.996  0.510  1.0
  Al  Al4  1  0.510  0.996  0.996  1.0
  Al  Al5  1  0.380  0.380  0.380  1.0
  O  O6  1  0.753  0.753  0.212  1.0
  O  O7  1  0.753  0.212  0.753  1.0
  O  O8  1  0.212  0.753  0.753  1.0
  O  O9  1  0.760  0.760  0.760  1.0
  O  O10  1  0.246  0.246  0.246  1.0
  O  O11  1  0.770  0.251  0.251  1.0
  O  O12  1  0.251  0.770  0.251  1.0
  O  O13  1  0.251  0.251  0.770  1.0
[/CIF]
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