The material described by MgFe2Si2SbO9 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Si(2)O4 tetrahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-50°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Mg(1)O5 trigonal bipyramids, and edges with three equivalent Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, edges with three equivalent Fe(1)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 53-58°. In the second Si site, Si(2) is bonded to one O(5), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 56-68°. Sb(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one Fe(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one Fe(1) and one Fe(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_MgFe2Si2SbO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.381
_cell_length_b   5.329
_cell_length_c   8.090
_cell_angle_alpha   101.287
_cell_angle_beta   90.865
_cell_angle_gamma   121.431
_symmetry_Int_Tables_number   1
_cell_volume   192.206
_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  0.397  0.805  0.302  1.0
  Fe  Fe1  1  0.629  0.333  0.992  1.0
  Fe  Fe2  1  0.302  0.620  0.960  1.0
  Si  Si3  1  0.882  0.523  0.637  1.0
  Si  Si4  1  0.561  0.864  0.651  1.0
  Sb  Sb5  1  0.065  0.108  0.261  1.0
  O  O6  1  0.040  0.413  0.164  1.0
  O  O7  1  0.362  0.040  0.146  1.0
  O  O8  1  0.677  0.728  0.163  1.0
  O  O9  1  0.936  0.570  0.838  1.0
  O  O10  1  0.618  0.963  0.852  1.0
  O  O11  1  0.332  0.280  0.849  1.0
  O  O12  1  0.206  0.668  0.557  1.0
  O  O13  1  0.687  0.143  0.543  1.0
  O  O14  1  0.701  0.662  0.567  1.0
[/CIF]
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The material described by MgFe2Si2SbO9 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Si(2)O4 tetrahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-50°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Mg(1)O5 trigonal bipyramids, and edges with three equivalent Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, edges with three equivalent Fe(1)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 53-58°. In the second Si site, Si(2) is bonded to one O(5), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 56-68°. Sb(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one Fe(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one Fe(1) and one Fe(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_MgFe2Si2SbO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.381
_cell_length_b   5.329
_cell_length_c   8.090
_cell_angle_alpha   101.287
_cell_angle_beta   90.865
_cell_angle_gamma   121.431
_symmetry_Int_Tables_number   1
_cell_volume   192.206
_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  0.397  0.805  0.302  1.0
  Fe  Fe1  1  0.629  0.333  0.992  1.0
  Fe  Fe2  1  0.302  0.620  0.960  1.0
  Si  Si3  1  0.882  0.523  0.637  1.0
  Si  Si4  1  0.561  0.864  0.651  1.0
  Sb  Sb5  1  0.065  0.108  0.261  1.0
  O  O6  1  0.040  0.413  0.164  1.0
  O  O7  1  0.362  0.040  0.146  1.0
  O  O8  1  0.677  0.728  0.163  1.0
  O  O9  1  0.936  0.570  0.838  1.0
  O  O10  1  0.618  0.963  0.852  1.0
  O  O11  1  0.332  0.280  0.849  1.0
  O  O12  1  0.206  0.668  0.557  1.0
  O  O13  1  0.687  0.143  0.543  1.0
  O  O14  1  0.701  0.662  0.567  1.0
[/CIF]
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