The material described by Fe2SiO4 crystallizes in the orthorhombic Imma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with six equivalent Si(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Si(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted FeO6 octahedra that share edges with two equivalent Fe(2)O6 octahedra, edges with four equivalent Fe(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SiO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Si(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(2), and one Si(1) atom. In the second O site, O(2) is bonded to one Fe(2), two equivalent Fe(1), and two equivalent Si(1) atoms to form a mixture of distorted corner and edge-sharing OFe3Si2 square pyramids. is represented by the CIF card [CIF]
data_Fe2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.761
_cell_length_b   5.761
_cell_length_c   5.761
_cell_angle_alpha   121.124
_cell_angle_beta   111.867
_cell_angle_gamma   96.353
_symmetry_Int_Tables_number   1
_cell_volume   140.371
_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
  Fe  Fe0  1  0.500  0.000  0.000  1.0
  Fe  Fe1  1  0.500  0.500  0.500  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.000  0.500  0.500  1.0
  Si  Si4  1  0.000  0.500  0.000  1.0
  Si  Si5  1  0.000  0.000  0.500  1.0
  O  O6  1  0.767  0.755  0.489  1.0
  O  O7  1  0.233  0.245  0.511  1.0
  O  O8  1  0.233  0.722  0.989  1.0
  O  O9  1  0.767  0.278  0.011  1.0
  O  O10  1  0.181  0.240  0.941  1.0
  O  O11  1  0.201  0.760  0.441  1.0
  O  O12  1  0.819  0.760  0.059  1.0
  O  O13  1  0.799  0.240  0.559  1.0
[/CIF]
.
The material described by Fe2SiO4 crystallizes in the orthorhombic Imma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with six equivalent Si(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Si(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted FeO6 octahedra that share edges with two equivalent Fe(2)O6 octahedra, edges with four equivalent Fe(1)O6 octahedra, and edges with four equivalent Si(1)O6 octahedra. Si(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SiO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Si(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(2), and one Si(1) atom. In the second O site, O(2) is bonded to one Fe(2), two equivalent Fe(1), and two equivalent Si(1) atoms to form a mixture of distorted corner and edge-sharing OFe3Si2 square pyramids. is represented by the CIF card [CIF]
data_Fe2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.761
_cell_length_b   5.761
_cell_length_c   5.761
_cell_angle_alpha   121.124
_cell_angle_beta   111.867
_cell_angle_gamma   96.353
_symmetry_Int_Tables_number   1
_cell_volume   140.371
_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
  Fe  Fe0  1  0.500  0.000  0.000  1.0
  Fe  Fe1  1  0.500  0.500  0.500  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.000  0.500  0.500  1.0
  Si  Si4  1  0.000  0.500  0.000  1.0
  Si  Si5  1  0.000  0.000  0.500  1.0
  O  O6  1  0.767  0.755  0.489  1.0
  O  O7  1  0.233  0.245  0.511  1.0
  O  O8  1  0.233  0.722  0.989  1.0
  O  O9  1  0.767  0.278  0.011  1.0
  O  O10  1  0.181  0.240  0.941  1.0
  O  O11  1  0.201  0.760  0.441  1.0
  O  O12  1  0.819  0.760  0.059  1.0
  O  O13  1  0.799  0.240  0.559  1.0
[/CIF]
.