The compound described by Mg2SiO4 crystallizes in the orthorhombic Pbam space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing SiO6 octahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded to three equivalent Mg(1) and two equivalent Si(1) atoms to form distorted OMg3Si2 trigonal bipyramids that share corners with four equivalent O(1)Mg4Si trigonal bipyramids, corners with eight equivalent O(2)Mg3Si2 trigonal bipyramids, edges with two equivalent O(2)Mg3Si2 trigonal bipyramids, and edges with six equivalent O(1)Mg4Si trigonal bipyramids. In the second O site, O(1) is bonded to four equivalent Mg(1) and one Si(1) atom to form distorted OMg4Si trigonal bipyramids that share corners with four equivalent O(2)Mg3Si2 trigonal bipyramids, corners with five equivalent O(1)Mg4Si trigonal bipyramids, edges with four equivalent O(1)Mg4Si trigonal bipyramids, and edges with six equivalent O(2)Mg3Si2 trigonal bipyramids. is represented by the CIF card [CIF]
data_Mg2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.841
_cell_length_b   5.045
_cell_length_c   8.883
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   127.335
_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  0.500  0.436  0.816  1.0
  Mg  Mg1  1  0.500  0.564  0.184  1.0
  Mg  Mg2  1  0.500  0.936  0.684  1.0
  Mg  Mg3  1  0.500  0.064  0.316  1.0
  Si  Si4  1  0.000  0.500  0.500  1.0
  Si  Si5  1  0.000  0.000  0.000  1.0
  O  O6  1  0.000  0.138  0.817  1.0
  O  O7  1  0.000  0.862  0.183  1.0
  O  O8  1  0.000  0.638  0.683  1.0
  O  O9  1  0.000  0.362  0.317  1.0
  O  O10  1  0.500  0.275  0.550  1.0
  O  O11  1  0.500  0.725  0.450  1.0
  O  O12  1  0.500  0.225  0.050  1.0
  O  O13  1  0.500  0.775  0.950  1.0
[/CIF]
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The compound described by Mg2SiO4 crystallizes in the orthorhombic Pbam space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing SiO6 octahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded to three equivalent Mg(1) and two equivalent Si(1) atoms to form distorted OMg3Si2 trigonal bipyramids that share corners with four equivalent O(1)Mg4Si trigonal bipyramids, corners with eight equivalent O(2)Mg3Si2 trigonal bipyramids, edges with two equivalent O(2)Mg3Si2 trigonal bipyramids, and edges with six equivalent O(1)Mg4Si trigonal bipyramids. In the second O site, O(1) is bonded to four equivalent Mg(1) and one Si(1) atom to form distorted OMg4Si trigonal bipyramids that share corners with four equivalent O(2)Mg3Si2 trigonal bipyramids, corners with five equivalent O(1)Mg4Si trigonal bipyramids, edges with four equivalent O(1)Mg4Si trigonal bipyramids, and edges with six equivalent O(2)Mg3Si2 trigonal bipyramids. is represented by the CIF card [CIF]
data_Mg2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.841
_cell_length_b   5.045
_cell_length_c   8.883
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   127.335
_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  0.500  0.436  0.816  1.0
  Mg  Mg1  1  0.500  0.564  0.184  1.0
  Mg  Mg2  1  0.500  0.936  0.684  1.0
  Mg  Mg3  1  0.500  0.064  0.316  1.0
  Si  Si4  1  0.000  0.500  0.500  1.0
  Si  Si5  1  0.000  0.000  0.000  1.0
  O  O6  1  0.000  0.138  0.817  1.0
  O  O7  1  0.000  0.862  0.183  1.0
  O  O8  1  0.000  0.638  0.683  1.0
  O  O9  1  0.000  0.362  0.317  1.0
  O  O10  1  0.500  0.275  0.550  1.0
  O  O11  1  0.500  0.725  0.450  1.0
  O  O12  1  0.500  0.225  0.050  1.0
  O  O13  1  0.500  0.775  0.950  1.0
[/CIF]
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