The structure described by MgY2Cr2O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(7), and one O(8) atom to form MgO4 tetrahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Y(2)O6 pentagonal pyramids, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Y site, Y(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted YO6 pentagonal pyramids that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form CrO6 octahedra that share edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Y(2)O6 pentagonal pyramids, and  an edgeedge with one Mg(1)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CrO6 octahedra that share corners with two equivalent Y(2)O6 pentagonal pyramids, corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Y(2)O6 pentagonal pyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Y(2), and one Cr(2) atom. In the second O site, O(2) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Y(2), and one Cr(2) atom. In the fourth O site, O(4) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mg(1), one Y(1), and one Cr(1) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Mg(1), one Y(1), and one Cr(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2MgCr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.046
_cell_length_b   5.149
_cell_length_c   7.896
_cell_angle_alpha   105.431
_cell_angle_beta   105.251
_cell_angle_gamma   100.198
_symmetry_Int_Tables_number   1
_cell_volume   183.963
_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  0.402  0.153  0.806  1.0
  Y  Y1  1  0.580  0.828  0.158  1.0
  Mg  Mg2  1  0.735  0.481  0.465  1.0
  Cr  Cr3  1  0.929  0.679  0.858  1.0
  Cr  Cr4  1  0.067  0.315  0.132  1.0
  O  O5  1  0.906  0.235  0.309  1.0
  O  O6  1  0.727  0.950  0.930  1.0
  O  O7  1  0.405  0.570  0.309  1.0
  O  O8  1  0.203  0.480  0.930  1.0
  O  O9  1  0.804  0.516  0.052  1.0
  O  O10  1  0.248  0.034  0.051  1.0
  O  O11  1  0.029  0.791  0.669  1.0
  O  O12  1  0.642  0.380  0.670  1.0
[/CIF]
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The structure described by MgY2Cr2O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(7), and one O(8) atom to form MgO4 tetrahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Y(2)O6 pentagonal pyramids, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Y site, Y(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted YO6 pentagonal pyramids that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form CrO6 octahedra that share edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Y(2)O6 pentagonal pyramids, and  an edgeedge with one Mg(1)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CrO6 octahedra that share corners with two equivalent Y(2)O6 pentagonal pyramids, corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Y(2)O6 pentagonal pyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Y(2), and one Cr(2) atom. In the second O site, O(2) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Y(2), and one Cr(2) atom. In the fourth O site, O(4) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Y(1), one Y(2), one Cr(1), and one Cr(2) atom to form a mixture of distorted corner and edge-sharing OY2Cr2 trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mg(1), one Y(1), and one Cr(1) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Mg(1), one Y(1), and one Cr(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2MgCr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.046
_cell_length_b   5.149
_cell_length_c   7.896
_cell_angle_alpha   105.431
_cell_angle_beta   105.251
_cell_angle_gamma   100.198
_symmetry_Int_Tables_number   1
_cell_volume   183.963
_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  0.402  0.153  0.806  1.0
  Y  Y1  1  0.580  0.828  0.158  1.0
  Mg  Mg2  1  0.735  0.481  0.465  1.0
  Cr  Cr3  1  0.929  0.679  0.858  1.0
  Cr  Cr4  1  0.067  0.315  0.132  1.0
  O  O5  1  0.906  0.235  0.309  1.0
  O  O6  1  0.727  0.950  0.930  1.0
  O  O7  1  0.405  0.570  0.309  1.0
  O  O8  1  0.203  0.480  0.930  1.0
  O  O9  1  0.804  0.516  0.052  1.0
  O  O10  1  0.248  0.034  0.051  1.0
  O  O11  1  0.029  0.791  0.669  1.0
  O  O12  1  0.642  0.380  0.670  1.0
[/CIF]
.