The crystal structure described by Cr(SiO3)2 crystallizes in the monoclinic C2/c space group. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted CrO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cr(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Cr(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.509
_cell_length_b   6.509
_cell_length_c   5.339
_cell_angle_alpha   74.806
_cell_angle_beta   74.806
_cell_angle_gamma   84.462
_symmetry_Int_Tables_number   1
_cell_volume   210.565
_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
  Cr  Cr0  1  0.398  0.602  0.750  1.0
  Cr  Cr1  1  0.602  0.398  0.250  1.0
  Si  Si2  1  0.284  0.114  0.745  1.0
  Si  Si3  1  0.716  0.886  0.255  1.0
  Si  Si4  1  0.886  0.716  0.755  1.0
  Si  Si5  1  0.114  0.284  0.245  1.0
  O  O6  1  0.864  0.854  0.464  1.0
  O  O7  1  0.401  0.880  0.779  1.0
  O  O8  1  0.684  0.545  0.873  1.0
  O  O9  1  0.136  0.146  0.536  1.0
  O  O10  1  0.599  0.120  0.221  1.0
  O  O11  1  0.316  0.455  0.127  1.0
  O  O12  1  0.120  0.599  0.721  1.0
  O  O13  1  0.455  0.316  0.627  1.0
  O  O14  1  0.854  0.864  0.964  1.0
  O  O15  1  0.146  0.136  0.036  1.0
  O  O16  1  0.545  0.684  0.373  1.0
  O  O17  1  0.880  0.401  0.279  1.0
[/CIF]
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The crystal structure described by Cr(SiO3)2 crystallizes in the monoclinic C2/c space group. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted CrO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cr(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Cr(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.509
_cell_length_b   6.509
_cell_length_c   5.339
_cell_angle_alpha   74.806
_cell_angle_beta   74.806
_cell_angle_gamma   84.462
_symmetry_Int_Tables_number   1
_cell_volume   210.565
_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
  Cr  Cr0  1  0.398  0.602  0.750  1.0
  Cr  Cr1  1  0.602  0.398  0.250  1.0
  Si  Si2  1  0.284  0.114  0.745  1.0
  Si  Si3  1  0.716  0.886  0.255  1.0
  Si  Si4  1  0.886  0.716  0.755  1.0
  Si  Si5  1  0.114  0.284  0.245  1.0
  O  O6  1  0.864  0.854  0.464  1.0
  O  O7  1  0.401  0.880  0.779  1.0
  O  O8  1  0.684  0.545  0.873  1.0
  O  O9  1  0.136  0.146  0.536  1.0
  O  O10  1  0.599  0.120  0.221  1.0
  O  O11  1  0.316  0.455  0.127  1.0
  O  O12  1  0.120  0.599  0.721  1.0
  O  O13  1  0.455  0.316  0.627  1.0
  O  O14  1  0.854  0.864  0.964  1.0
  O  O15  1  0.146  0.136  0.036  1.0
  O  O16  1  0.545  0.684  0.373  1.0
  O  O17  1  0.880  0.401  0.279  1.0
[/CIF]
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