The compound described by Mg3SiO6 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with eight equivalent Mg(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Mg(2)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-57°. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-60°. Si(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the second O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mg(2) atoms. is represented by the CIF file [CIF]
data_Mg3SiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.803
_cell_length_b   8.966
_cell_length_c   10.464
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   450.591
_cell_formula_units_Z   4
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  0.500  0.750  0.594  1.0
  Mg  Mg1  1  0.500  0.250  0.406  1.0
  Mg  Mg2  1  1.000  0.250  0.906  1.0
  Mg  Mg3  1  0.000  0.750  0.094  1.0
  Mg  Mg4  1  0.512  0.570  0.866  1.0
  Mg  Mg5  1  0.488  0.430  0.134  1.0
  Mg  Mg6  1  0.012  0.430  0.634  1.0
  Mg  Mg7  1  0.488  0.070  0.134  1.0
  Mg  Mg8  1  0.988  0.570  0.366  1.0
  Mg  Mg9  1  0.512  0.930  0.866  1.0
  Mg  Mg10  1  0.988  0.930  0.366  1.0
  Mg  Mg11  1  0.012  0.070  0.634  1.0
  Si  Si12  1  0.076  0.750  0.780  1.0
  Si  Si13  1  0.924  0.250  0.220  1.0
  Si  Si14  1  0.576  0.250  0.720  1.0
  Si  Si15  1  0.424  0.750  0.280  1.0
  O  O16  1  0.726  0.106  0.792  1.0
  O  O17  1  0.274  0.894  0.208  1.0
  O  O18  1  0.226  0.894  0.708  1.0
  O  O19  1  0.274  0.606  0.208  1.0
  O  O20  1  0.774  0.106  0.292  1.0
  O  O21  1  0.726  0.394  0.792  1.0
  O  O22  1  0.774  0.394  0.292  1.0
  O  O23  1  0.226  0.606  0.708  1.0
  O  O24  1  0.768  0.585  0.536  1.0
  O  O25  1  0.232  0.415  0.464  1.0
  O  O26  1  0.268  0.415  0.964  1.0
  O  O27  1  0.232  0.085  0.464  1.0
  O  O28  1  0.732  0.585  0.036  1.0
  O  O29  1  0.768  0.915  0.536  1.0
  O  O30  1  0.732  0.915  0.036  1.0
  O  O31  1  0.268  0.085  0.964  1.0
  O  O32  1  0.737  0.750  0.779  1.0
  O  O33  1  0.263  0.250  0.221  1.0
  O  O34  1  0.237  0.250  0.721  1.0
  O  O35  1  0.763  0.750  0.279  1.0
  O  O36  1  0.223  0.750  0.924  1.0
  O  O37  1  0.777  0.250  0.076  1.0
  O  O38  1  0.723  0.250  0.576  1.0
  O  O39  1  0.277  0.750  0.424  1.0
[/CIF]
.
The compound described by Mg3SiO6 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with eight equivalent Mg(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Mg(2)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-57°. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-60°. Si(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the second O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mg(2) atoms. is represented by the CIF file [CIF]
data_Mg3SiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.803
_cell_length_b   8.966
_cell_length_c   10.464
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   450.591
_cell_formula_units_Z   4
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  0.500  0.750  0.594  1.0
  Mg  Mg1  1  0.500  0.250  0.406  1.0
  Mg  Mg2  1  1.000  0.250  0.906  1.0
  Mg  Mg3  1  0.000  0.750  0.094  1.0
  Mg  Mg4  1  0.512  0.570  0.866  1.0
  Mg  Mg5  1  0.488  0.430  0.134  1.0
  Mg  Mg6  1  0.012  0.430  0.634  1.0
  Mg  Mg7  1  0.488  0.070  0.134  1.0
  Mg  Mg8  1  0.988  0.570  0.366  1.0
  Mg  Mg9  1  0.512  0.930  0.866  1.0
  Mg  Mg10  1  0.988  0.930  0.366  1.0
  Mg  Mg11  1  0.012  0.070  0.634  1.0
  Si  Si12  1  0.076  0.750  0.780  1.0
  Si  Si13  1  0.924  0.250  0.220  1.0
  Si  Si14  1  0.576  0.250  0.720  1.0
  Si  Si15  1  0.424  0.750  0.280  1.0
  O  O16  1  0.726  0.106  0.792  1.0
  O  O17  1  0.274  0.894  0.208  1.0
  O  O18  1  0.226  0.894  0.708  1.0
  O  O19  1  0.274  0.606  0.208  1.0
  O  O20  1  0.774  0.106  0.292  1.0
  O  O21  1  0.726  0.394  0.792  1.0
  O  O22  1  0.774  0.394  0.292  1.0
  O  O23  1  0.226  0.606  0.708  1.0
  O  O24  1  0.768  0.585  0.536  1.0
  O  O25  1  0.232  0.415  0.464  1.0
  O  O26  1  0.268  0.415  0.964  1.0
  O  O27  1  0.232  0.085  0.464  1.0
  O  O28  1  0.732  0.585  0.036  1.0
  O  O29  1  0.768  0.915  0.536  1.0
  O  O30  1  0.732  0.915  0.036  1.0
  O  O31  1  0.268  0.085  0.964  1.0
  O  O32  1  0.737  0.750  0.779  1.0
  O  O33  1  0.263  0.250  0.221  1.0
  O  O34  1  0.237  0.250  0.721  1.0
  O  O35  1  0.763  0.750  0.279  1.0
  O  O36  1  0.223  0.750  0.924  1.0
  O  O37  1  0.777  0.250  0.076  1.0
  O  O38  1  0.723  0.250  0.576  1.0
  O  O39  1  0.277  0.750  0.424  1.0
[/CIF]
.