The material structure described by MgY2Cr3O9 crystallizes in the tetragonal P4/mmm space group. Mg(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. Y(1) is bonded in a 4-coordinate geometry to four equivalent O(1) and four equivalent O(4) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedra are not tilted. In the second Cr site, Cr(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), and four equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Y(1), one Cr(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Cr(2) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Y(1) and two equivalent Cr(2) atoms. is represented by the CIF file [CIF]
data_Y2MgCr3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.875
_cell_length_b   3.875
_cell_length_c   13.016
_cell_angle_alpha   90.022
_cell_angle_beta   89.972
_cell_angle_gamma   89.993
_symmetry_Int_Tables_number   1
_cell_volume   195.458
_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
  Y  Y0  1  1.000  0.000  0.929  1.0
  Y  Y1  1  0.000  1.000  0.405  1.0
  Mg  Mg2  1  1.000  1.000  0.167  1.0
  Cr  Cr3  1  0.500  0.500  0.167  1.0
  Cr  Cr4  1  0.500  0.500  0.528  1.0
  Cr  Cr5  1  0.500  0.500  0.805  1.0
  O  O6  1  0.500  0.500  0.999  1.0
  O  O7  1  0.500  0.500  0.335  1.0
  O  O8  1  0.500  0.500  0.667  1.0
  O  O9  1  0.500  1.000  0.167  1.0
  O  O10  1  0.500  1.000  0.495  1.0
  O  O11  1  0.500  0.000  0.838  1.0
  O  O12  1  0.000  0.500  0.167  1.0
  O  O13  1  0.000  0.500  0.495  1.0
  O  O14  1  1.000  0.500  0.838  1.0
[/CIF]
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The material structure described by MgY2Cr3O9 crystallizes in the tetragonal P4/mmm space group. Mg(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. Y(1) is bonded in a 4-coordinate geometry to four equivalent O(1) and four equivalent O(4) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedra are not tilted. In the second Cr site, Cr(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), and four equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Y(1), one Cr(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Cr(2) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Y(1) and two equivalent Cr(2) atoms. is represented by the CIF file [CIF]
data_Y2MgCr3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.875
_cell_length_b   3.875
_cell_length_c   13.016
_cell_angle_alpha   90.022
_cell_angle_beta   89.972
_cell_angle_gamma   89.993
_symmetry_Int_Tables_number   1
_cell_volume   195.458
_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
  Y  Y0  1  1.000  0.000  0.929  1.0
  Y  Y1  1  0.000  1.000  0.405  1.0
  Mg  Mg2  1  1.000  1.000  0.167  1.0
  Cr  Cr3  1  0.500  0.500  0.167  1.0
  Cr  Cr4  1  0.500  0.500  0.528  1.0
  Cr  Cr5  1  0.500  0.500  0.805  1.0
  O  O6  1  0.500  0.500  0.999  1.0
  O  O7  1  0.500  0.500  0.335  1.0
  O  O8  1  0.500  0.500  0.667  1.0
  O  O9  1  0.500  1.000  0.167  1.0
  O  O10  1  0.500  1.000  0.495  1.0
  O  O11  1  0.500  0.000  0.838  1.0
  O  O12  1  0.000  0.500  0.167  1.0
  O  O13  1  0.000  0.500  0.495  1.0
  O  O14  1  1.000  0.500  0.838  1.0
[/CIF]
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