The material described by Mg3FeO4 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fourth Mg site, Mg(4) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with three equivalent Mg(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form FeO6 octahedra that share corners with three equivalent Mg(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, edges with three equivalent Mg(3)O6 octahedra, edges with three equivalent Mg(4)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(3), two equivalent Mg(4), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share corners with three equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg6 octahedra,  an edgeedge with one O(3)Mg6 octahedra, edges with two equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)Mg3Fe3 octahedra, and edges with five equivalent O(2)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Mg(4), two equivalent Mg(3), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share corners with three equivalent O(1)Mg3Fe3 octahedra, corners with three equivalent O(4)Mg6 octahedra,  an edgeedge with one O(4)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, edges with four equivalent O(2)Mg3Fe3 octahedra, and edges with five equivalent O(1)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(3) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with three equivalent O(1)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg6 octahedra,  an edgeedge with one O(1)Mg3Fe3 octahedra, edges with two equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(3)Mg6 octahedra, and edges with six equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(4) is bonded to one Mg(2), one Mg(4), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with three equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(4)Mg6 octahedra,  an edgeedge with one O(2)Mg3Fe3 octahedra, edges with two equivalent O(1)Mg3Fe3 octahedra, edges with three equivalent O(4)Mg6 octahedra, and edges with six equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_Mg3FeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.017
_cell_length_b   3.021
_cell_length_c   10.101
_cell_angle_alpha   90.877
_cell_angle_beta   97.853
_cell_angle_gamma   119.447
_symmetry_Int_Tables_number   1
_cell_volume   79.068
_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
  Fe  Fe0  1  0.000  1.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.500  1.0
  Mg  Mg2  1  0.504  0.750  0.254  1.0
  Mg  Mg3  1  0.496  0.250  0.746  1.0
  O  O4  1  0.236  0.632  0.867  1.0
  O  O5  1  0.764  0.368  0.133  1.0
  O  O6  1  0.748  0.875  0.623  1.0
  O  O7  1  0.252  0.125  0.377  1.0
[/CIF]
.
The material described by Mg3FeO4 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fourth Mg site, Mg(4) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with three equivalent Mg(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form FeO6 octahedra that share corners with three equivalent Mg(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, edges with three equivalent Mg(3)O6 octahedra, edges with three equivalent Mg(4)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(3), two equivalent Mg(4), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share corners with three equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg6 octahedra,  an edgeedge with one O(3)Mg6 octahedra, edges with two equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)Mg3Fe3 octahedra, and edges with five equivalent O(2)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Mg(4), two equivalent Mg(3), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share corners with three equivalent O(1)Mg3Fe3 octahedra, corners with three equivalent O(4)Mg6 octahedra,  an edgeedge with one O(4)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, edges with four equivalent O(2)Mg3Fe3 octahedra, and edges with five equivalent O(1)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(3) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with three equivalent O(1)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg6 octahedra,  an edgeedge with one O(1)Mg3Fe3 octahedra, edges with two equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(3)Mg6 octahedra, and edges with six equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(4) is bonded to one Mg(2), one Mg(4), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with three equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(4)Mg6 octahedra,  an edgeedge with one O(2)Mg3Fe3 octahedra, edges with two equivalent O(1)Mg3Fe3 octahedra, edges with three equivalent O(4)Mg6 octahedra, and edges with six equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_Mg3FeO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.017
_cell_length_b   3.021
_cell_length_c   10.101
_cell_angle_alpha   90.877
_cell_angle_beta   97.853
_cell_angle_gamma   119.447
_symmetry_Int_Tables_number   1
_cell_volume   79.068
_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
  Fe  Fe0  1  0.000  1.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.500  1.0
  Mg  Mg2  1  0.504  0.750  0.254  1.0
  Mg  Mg3  1  0.496  0.250  0.746  1.0
  O  O4  1  0.236  0.632  0.867  1.0
  O  O5  1  0.764  0.368  0.133  1.0
  O  O6  1  0.748  0.875  0.623  1.0
  O  O7  1  0.252  0.125  0.377  1.0
[/CIF]
.