The compound described by Mg2SiO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing SiO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(2) is bonded to four equivalent Mg(1) and two equivalent Si(1) atoms to form distorted OMg4Si2 octahedra that share corners with two equivalent O(2)Mg4Si2 octahedra, corners with twelve equivalent O(1)Mg5Si octahedra, edges with two equivalent O(2)Mg4Si2 octahedra, faces with four equivalent O(2)Mg4Si2 octahedra, and faces with four equivalent O(1)Mg5Si octahedra. The corner-sharing octahedral tilt angles range from 0-55°. In the second O site, O(1) is bonded to five equivalent Mg(1) and one Si(1) atom to form distorted OMg5Si octahedra that share corners with five equivalent O(1)Mg5Si octahedra, corners with twelve equivalent O(2)Mg4Si2 octahedra, edges with eight equivalent O(1)Mg5Si octahedra, and faces with four equivalent O(2)Mg4Si2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.500
_cell_length_b   3.500
_cell_length_c   5.910
_cell_angle_alpha   107.223
_cell_angle_beta   107.223
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   65.734
_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  0.650  0.650  0.300  1.0
  Mg  Mg1  1  0.350  0.350  0.700  1.0
  Si  Si2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.833  0.833  0.666  1.0
  O  O4  1  0.167  0.167  0.334  1.0
  O  O5  1  0.000  0.500  0.000  1.0
  O  O6  1  0.500  0.000  0.000  1.0
[/CIF]
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The compound described by Mg2SiO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing SiO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(2) is bonded to four equivalent Mg(1) and two equivalent Si(1) atoms to form distorted OMg4Si2 octahedra that share corners with two equivalent O(2)Mg4Si2 octahedra, corners with twelve equivalent O(1)Mg5Si octahedra, edges with two equivalent O(2)Mg4Si2 octahedra, faces with four equivalent O(2)Mg4Si2 octahedra, and faces with four equivalent O(1)Mg5Si octahedra. The corner-sharing octahedral tilt angles range from 0-55°. In the second O site, O(1) is bonded to five equivalent Mg(1) and one Si(1) atom to form distorted OMg5Si octahedra that share corners with five equivalent O(1)Mg5Si octahedra, corners with twelve equivalent O(2)Mg4Si2 octahedra, edges with eight equivalent O(1)Mg5Si octahedra, and faces with four equivalent O(2)Mg4Si2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.500
_cell_length_b   3.500
_cell_length_c   5.910
_cell_angle_alpha   107.223
_cell_angle_beta   107.223
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   65.734
_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  0.650  0.650  0.300  1.0
  Mg  Mg1  1  0.350  0.350  0.700  1.0
  Si  Si2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.833  0.833  0.666  1.0
  O  O4  1  0.167  0.167  0.334  1.0
  O  O5  1  0.000  0.500  0.000  1.0
  O  O6  1  0.500  0.000  0.000  1.0
[/CIF]
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