The structure described by CrZn(SiO3)2 is Esseneite structured and 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 CrO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cr(1)O6 octahedra. Zn(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. 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 40-64°. 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 3-coordinate geometry to one Cr(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Cr(1), one Zn(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_ZnCr(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.352
_cell_length_b   6.945
_cell_length_c   6.945
_cell_angle_alpha   87.998
_cell_angle_beta   74.760
_cell_angle_gamma   74.763
_symmetry_Int_Tables_number   1
_cell_volume   240.149
_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
  Zn  Zn0  1  0.750  0.241  0.759  1.0
  Zn  Zn1  1  0.250  0.759  0.241  1.0
  Cr  Cr2  1  0.750  0.899  0.101  1.0
  Cr  Cr3  1  0.250  0.101  0.899  1.0
  Si  Si4  1  0.228  0.217  0.385  1.0
  Si  Si5  1  0.272  0.615  0.783  1.0
  Si  Si6  1  0.728  0.385  0.217  1.0
  Si  Si7  1  0.772  0.783  0.615  1.0
  O  O8  1  0.473  0.323  0.375  1.0
  O  O9  1  0.027  0.625  0.677  1.0
  O  O10  1  0.527  0.677  0.625  1.0
  O  O11  1  0.973  0.375  0.323  1.0
  O  O12  1  0.121  0.151  0.612  1.0
  O  O13  1  0.379  0.388  0.849  1.0
  O  O14  1  0.879  0.850  0.388  1.0
  O  O15  1  0.621  0.612  0.151  1.0
  O  O16  1  0.848  0.215  0.032  1.0
  O  O17  1  0.652  0.968  0.785  1.0
  O  O18  1  0.348  0.032  0.215  1.0
  O  O19  1  0.152  0.785  0.968  1.0
[/CIF]
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The structure described by CrZn(SiO3)2 is Esseneite structured and 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 CrO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cr(1)O6 octahedra. Zn(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. 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 40-64°. 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 3-coordinate geometry to one Cr(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Cr(1), one Zn(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_ZnCr(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.352
_cell_length_b   6.945
_cell_length_c   6.945
_cell_angle_alpha   87.998
_cell_angle_beta   74.760
_cell_angle_gamma   74.763
_symmetry_Int_Tables_number   1
_cell_volume   240.149
_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
  Zn  Zn0  1  0.750  0.241  0.759  1.0
  Zn  Zn1  1  0.250  0.759  0.241  1.0
  Cr  Cr2  1  0.750  0.899  0.101  1.0
  Cr  Cr3  1  0.250  0.101  0.899  1.0
  Si  Si4  1  0.228  0.217  0.385  1.0
  Si  Si5  1  0.272  0.615  0.783  1.0
  Si  Si6  1  0.728  0.385  0.217  1.0
  Si  Si7  1  0.772  0.783  0.615  1.0
  O  O8  1  0.473  0.323  0.375  1.0
  O  O9  1  0.027  0.625  0.677  1.0
  O  O10  1  0.527  0.677  0.625  1.0
  O  O11  1  0.973  0.375  0.323  1.0
  O  O12  1  0.121  0.151  0.612  1.0
  O  O13  1  0.379  0.388  0.849  1.0
  O  O14  1  0.879  0.850  0.388  1.0
  O  O15  1  0.621  0.612  0.151  1.0
  O  O16  1  0.848  0.215  0.032  1.0
  O  O17  1  0.652  0.968  0.785  1.0
  O  O18  1  0.348  0.032  0.215  1.0
  O  O19  1  0.152  0.785  0.968  1.0
[/CIF]
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