The material described by Rb2MgFe4O7 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), and three equivalent O(3) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), one O(6), and three equivalent O(3) atoms. Mg(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-10°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(7) atom. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share corners with three equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(4)O6 octahedra, and  a cornercorner with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-61°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with three equivalent Fe(4)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with three equivalent Fe(3)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(2), one Fe(2), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted linear geometry to three equivalent Rb(1), three equivalent Rb(2), one Mg(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Rb(2), one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Rb(2), one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. is represented by the CIF file [CIF]
data_Rb2MgFe4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.491
_cell_length_b   5.660
_cell_length_c   7.996
_cell_angle_alpha   102.787
_cell_angle_beta   82.376
_cell_angle_gamma   122.578
_symmetry_Int_Tables_number   1
_cell_volume   204.180
_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
  Rb  Rb0  1  0.346  0.834  0.047  1.0
  Rb  Rb1  1  0.669  0.463  0.905  1.0
  Mg  Mg2  1  1.000  0.210  0.211  1.0
  Fe  Fe3  1  0.984  0.891  0.418  1.0
  Fe  Fe4  1  0.007  0.076  0.727  1.0
  Fe  Fe5  1  0.339  0.644  0.499  1.0
  Fe  Fe6  1  0.648  0.293  0.486  1.0
  O  O7  1  0.019  0.551  0.338  1.0
  O  O8  1  0.025  0.385  0.654  1.0
  O  O9  1  0.995  0.124  0.967  1.0
  O  O10  1  0.313  0.256  0.337  1.0
  O  O11  1  0.676  0.708  0.623  1.0
  O  O12  1  0.315  0.003  0.626  1.0
  O  O13  1  0.665  0.912  0.330  1.0
[/CIF]
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The material described by Rb2MgFe4O7 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), and three equivalent O(3) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), one O(6), and three equivalent O(3) atoms. Mg(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra,  a cornercorner with one Fe(2)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-10°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(7) atom. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share corners with three equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(4)O6 octahedra, and  a cornercorner with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-61°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with three equivalent Fe(4)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with three equivalent Fe(3)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(2), one Fe(2), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted linear geometry to three equivalent Rb(1), three equivalent Rb(2), one Mg(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Rb(2), one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Rb(2), one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one Rb(1), one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. is represented by the CIF file [CIF]
data_Rb2MgFe4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.491
_cell_length_b   5.660
_cell_length_c   7.996
_cell_angle_alpha   102.787
_cell_angle_beta   82.376
_cell_angle_gamma   122.578
_symmetry_Int_Tables_number   1
_cell_volume   204.180
_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
  Rb  Rb0  1  0.346  0.834  0.047  1.0
  Rb  Rb1  1  0.669  0.463  0.905  1.0
  Mg  Mg2  1  1.000  0.210  0.211  1.0
  Fe  Fe3  1  0.984  0.891  0.418  1.0
  Fe  Fe4  1  0.007  0.076  0.727  1.0
  Fe  Fe5  1  0.339  0.644  0.499  1.0
  Fe  Fe6  1  0.648  0.293  0.486  1.0
  O  O7  1  0.019  0.551  0.338  1.0
  O  O8  1  0.025  0.385  0.654  1.0
  O  O9  1  0.995  0.124  0.967  1.0
  O  O10  1  0.313  0.256  0.337  1.0
  O  O11  1  0.676  0.708  0.623  1.0
  O  O12  1  0.315  0.003  0.626  1.0
  O  O13  1  0.665  0.912  0.330  1.0
[/CIF]
.