The material structure described by Mg3Si4(SbO7)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), and two equivalent O(7) atoms. In the second Mg site, Mg(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Mg(2)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Sb site, Sb(2) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mg(2), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(2), one Si(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Si(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3Si4(SbO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.512
_cell_length_b   9.512
_cell_length_c   10.518
_cell_angle_alpha   59.636
_cell_angle_beta   59.636
_cell_angle_gamma   51.426
_symmetry_Int_Tables_number   1
_cell_volume   615.846
_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  0.033  0.305  0.103  1.0
  Mg  Mg1  1  0.695  0.967  0.397  1.0
  Mg  Mg2  1  0.305  0.033  0.603  1.0
  Mg  Mg3  1  0.413  0.587  0.750  1.0
  Mg  Mg4  1  0.967  0.695  0.897  1.0
  Mg  Mg5  1  0.587  0.413  0.250  1.0
  Si  Si6  1  0.528  0.085  0.713  1.0
  Si  Si7  1  0.085  0.528  0.213  1.0
  Si  Si8  1  0.491  0.267  0.116  1.0
  Si  Si9  1  0.267  0.491  0.616  1.0
  Si  Si10  1  0.915  0.472  0.787  1.0
  Si  Si11  1  0.509  0.733  0.884  1.0
  Si  Si12  1  0.733  0.509  0.384  1.0
  Si  Si13  1  0.472  0.915  0.287  1.0
  Sb  Sb14  1  0.796  0.204  0.750  1.0
  Sb  Sb15  1  0.204  0.796  0.250  1.0
  Sb  Sb16  1  0.000  0.000  0.000  1.0
  Sb  Sb17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.808  0.345  0.308  1.0
  O  O19  1  0.939  0.897  0.401  1.0
  O  O20  1  0.500  0.607  0.060  1.0
  O  O21  1  0.897  0.939  0.901  1.0
  O  O22  1  0.264  0.956  0.312  1.0
  O  O23  1  0.077  0.506  0.631  1.0
  O  O24  1  0.607  0.500  0.560  1.0
  O  O25  1  0.044  0.736  0.188  1.0
  O  O26  1  0.923  0.494  0.369  1.0
  O  O27  1  0.629  0.708  0.257  1.0
  O  O28  1  0.061  0.103  0.599  1.0
  O  O29  1  0.736  0.044  0.688  1.0
  O  O30  1  0.494  0.923  0.869  1.0
  O  O31  1  0.345  0.808  0.808  1.0
  O  O32  1  0.708  0.629  0.757  1.0
  O  O33  1  0.956  0.264  0.812  1.0
  O  O34  1  0.922  0.494  0.927  1.0
  O  O35  1  0.371  0.292  0.743  1.0
  O  O36  1  0.506  0.078  0.573  1.0
  O  O37  1  0.292  0.371  0.243  1.0
  O  O38  1  0.506  0.077  0.131  1.0
  O  O39  1  0.103  0.061  0.099  1.0
  O  O40  1  0.494  0.922  0.427  1.0
  O  O41  1  0.500  0.393  0.940  1.0
  O  O42  1  0.078  0.506  0.073  1.0
  O  O43  1  0.393  0.500  0.440  1.0
  O  O44  1  0.655  0.192  0.192  1.0
  O  O45  1  0.192  0.655  0.692  1.0
[/CIF]
.
The material structure described by Mg3Si4(SbO7)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), and two equivalent O(7) atoms. In the second Mg site, Mg(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Mg(2)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Sb site, Sb(2) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mg(2), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(2), one Si(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Si(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3Si4(SbO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.512
_cell_length_b   9.512
_cell_length_c   10.518
_cell_angle_alpha   59.636
_cell_angle_beta   59.636
_cell_angle_gamma   51.426
_symmetry_Int_Tables_number   1
_cell_volume   615.846
_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  0.033  0.305  0.103  1.0
  Mg  Mg1  1  0.695  0.967  0.397  1.0
  Mg  Mg2  1  0.305  0.033  0.603  1.0
  Mg  Mg3  1  0.413  0.587  0.750  1.0
  Mg  Mg4  1  0.967  0.695  0.897  1.0
  Mg  Mg5  1  0.587  0.413  0.250  1.0
  Si  Si6  1  0.528  0.085  0.713  1.0
  Si  Si7  1  0.085  0.528  0.213  1.0
  Si  Si8  1  0.491  0.267  0.116  1.0
  Si  Si9  1  0.267  0.491  0.616  1.0
  Si  Si10  1  0.915  0.472  0.787  1.0
  Si  Si11  1  0.509  0.733  0.884  1.0
  Si  Si12  1  0.733  0.509  0.384  1.0
  Si  Si13  1  0.472  0.915  0.287  1.0
  Sb  Sb14  1  0.796  0.204  0.750  1.0
  Sb  Sb15  1  0.204  0.796  0.250  1.0
  Sb  Sb16  1  0.000  0.000  0.000  1.0
  Sb  Sb17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.808  0.345  0.308  1.0
  O  O19  1  0.939  0.897  0.401  1.0
  O  O20  1  0.500  0.607  0.060  1.0
  O  O21  1  0.897  0.939  0.901  1.0
  O  O22  1  0.264  0.956  0.312  1.0
  O  O23  1  0.077  0.506  0.631  1.0
  O  O24  1  0.607  0.500  0.560  1.0
  O  O25  1  0.044  0.736  0.188  1.0
  O  O26  1  0.923  0.494  0.369  1.0
  O  O27  1  0.629  0.708  0.257  1.0
  O  O28  1  0.061  0.103  0.599  1.0
  O  O29  1  0.736  0.044  0.688  1.0
  O  O30  1  0.494  0.923  0.869  1.0
  O  O31  1  0.345  0.808  0.808  1.0
  O  O32  1  0.708  0.629  0.757  1.0
  O  O33  1  0.956  0.264  0.812  1.0
  O  O34  1  0.922  0.494  0.927  1.0
  O  O35  1  0.371  0.292  0.743  1.0
  O  O36  1  0.506  0.078  0.573  1.0
  O  O37  1  0.292  0.371  0.243  1.0
  O  O38  1  0.506  0.077  0.131  1.0
  O  O39  1  0.103  0.061  0.099  1.0
  O  O40  1  0.494  0.922  0.427  1.0
  O  O41  1  0.500  0.393  0.940  1.0
  O  O42  1  0.078  0.506  0.073  1.0
  O  O43  1  0.393  0.500  0.440  1.0
  O  O44  1  0.655  0.192  0.192  1.0
  O  O45  1  0.192  0.655  0.692  1.0
[/CIF]
.