The material structure described by Mg7(SiO4)4 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. In the third Mg site, Mg(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(5)O6 octahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles are 16°. In the fifth Mg site, Mg(5) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one Mg(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-62°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one Mg(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(4), and one Si(1) atom. In the second O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(5), and one Si(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(4), and one Si(2) atom. In the fourth O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(3), one Mg(5), and one Si(1) atom. In the fifth O site, O(3) is bonded in a see-saw-like geometry to one Mg(2), one Mg(3), one Mg(4), and one Mg(5) atom. In the sixth O site, O(4) is bonded in a trigonal planar geometry to one Mg(2), one Si(1), and one Si(2) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(2), and one Si(1) atom. In the eighth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(3), and one Si(2) atom. is represented by the CIF card [CIF]
data_Mg7(SiO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.707
_cell_length_b   7.707
_cell_length_c   5.684
_cell_angle_alpha   69.868
_cell_angle_beta   69.868
_cell_angle_gamma   99.860
_symmetry_Int_Tables_number   1
_cell_volume   281.119
_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  0.013  0.520  0.998  1.0
  Mg  Mg1  1  0.480  0.987  0.002  1.0
  Mg  Mg2  1  0.723  0.719  0.037  1.0
  Mg  Mg3  1  0.281  0.277  0.963  1.0
  Mg  Mg4  1  0.860  0.140  0.500  1.0
  Mg  Mg5  1  0.123  0.877  0.500  1.0
  Mg  Mg6  1  0.875  0.125  0.000  1.0
  Si  Si7  1  0.497  0.237  0.381  1.0
  Si  Si8  1  0.514  0.762  0.605  1.0
  Si  Si9  1  0.763  0.503  0.619  1.0
  Si  Si10  1  0.238  0.486  0.395  1.0
  O  O11  1  0.280  0.739  0.721  1.0
  O  O12  1  0.732  0.257  0.250  1.0
  O  O13  1  0.261  0.720  0.279  1.0
  O  O14  1  0.743  0.268  0.750  1.0
  O  O15  1  0.959  0.977  0.767  1.0
  O  O16  1  0.023  0.041  0.233  1.0
  O  O17  1  0.465  0.463  0.283  1.0
  O  O18  1  0.537  0.535  0.717  1.0
  O  O19  1  0.856  0.604  0.281  1.0
  O  O20  1  0.127  0.382  0.252  1.0
  O  O21  1  0.380  0.124  0.252  1.0
  O  O22  1  0.624  0.873  0.262  1.0
  O  O23  1  0.127  0.376  0.738  1.0
  O  O24  1  0.876  0.620  0.748  1.0
  O  O25  1  0.618  0.873  0.748  1.0
  O  O26  1  0.396  0.144  0.719  1.0
[/CIF]
.
The material structure described by Mg7(SiO4)4 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. In the third Mg site, Mg(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(5)O6 octahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles are 16°. In the fifth Mg site, Mg(5) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one Mg(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-62°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one Mg(5)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(4), and one Si(1) atom. In the second O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(5), and one Si(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(4), and one Si(2) atom. In the fourth O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(3), one Mg(5), and one Si(1) atom. In the fifth O site, O(3) is bonded in a see-saw-like geometry to one Mg(2), one Mg(3), one Mg(4), and one Mg(5) atom. In the sixth O site, O(4) is bonded in a trigonal planar geometry to one Mg(2), one Si(1), and one Si(2) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(2), and one Si(1) atom. In the eighth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(3), and one Si(2) atom. is represented by the CIF card [CIF]
data_Mg7(SiO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.707
_cell_length_b   7.707
_cell_length_c   5.684
_cell_angle_alpha   69.868
_cell_angle_beta   69.868
_cell_angle_gamma   99.860
_symmetry_Int_Tables_number   1
_cell_volume   281.119
_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  0.013  0.520  0.998  1.0
  Mg  Mg1  1  0.480  0.987  0.002  1.0
  Mg  Mg2  1  0.723  0.719  0.037  1.0
  Mg  Mg3  1  0.281  0.277  0.963  1.0
  Mg  Mg4  1  0.860  0.140  0.500  1.0
  Mg  Mg5  1  0.123  0.877  0.500  1.0
  Mg  Mg6  1  0.875  0.125  0.000  1.0
  Si  Si7  1  0.497  0.237  0.381  1.0
  Si  Si8  1  0.514  0.762  0.605  1.0
  Si  Si9  1  0.763  0.503  0.619  1.0
  Si  Si10  1  0.238  0.486  0.395  1.0
  O  O11  1  0.280  0.739  0.721  1.0
  O  O12  1  0.732  0.257  0.250  1.0
  O  O13  1  0.261  0.720  0.279  1.0
  O  O14  1  0.743  0.268  0.750  1.0
  O  O15  1  0.959  0.977  0.767  1.0
  O  O16  1  0.023  0.041  0.233  1.0
  O  O17  1  0.465  0.463  0.283  1.0
  O  O18  1  0.537  0.535  0.717  1.0
  O  O19  1  0.856  0.604  0.281  1.0
  O  O20  1  0.127  0.382  0.252  1.0
  O  O21  1  0.380  0.124  0.252  1.0
  O  O22  1  0.624  0.873  0.262  1.0
  O  O23  1  0.127  0.376  0.738  1.0
  O  O24  1  0.876  0.620  0.748  1.0
  O  O25  1  0.618  0.873  0.748  1.0
  O  O26  1  0.396  0.144  0.719  1.0
[/CIF]
.