The compound described by Er2Zr2O7 crystallizes in the monoclinic C2/m space group. Er(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted ErO6 pentagonal pyramids that share corners with four equivalent Zr(1)O5 trigonal bipyramids, edges with three equivalent Er(1)O6 pentagonal pyramids, and edges with two equivalent Zr(1)O5 trigonal bipyramids. Zr(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted ZrO5 trigonal bipyramids that share corners with four equivalent Er(1)O6 pentagonal pyramids,  a cornercorner with one Zr(1)O5 trigonal bipyramid, edges with two equivalent Er(1)O6 pentagonal pyramids, and  an edgeedge with one Zr(1)O5 trigonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Zr(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Zr(1) atom. In the third O site, O(3) is bonded to two equivalent Er(1) and two equivalent Zr(1) atoms to form edge-sharing OEr2Zr2 trigonal pyramids. is represented by the CIF file [CIF]
data_Er2Zr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.880
_cell_length_b   5.880
_cell_length_c   5.614
_cell_angle_alpha   83.876
_cell_angle_beta   83.876
_cell_angle_gamma   107.693
_symmetry_Int_Tables_number   1
_cell_volume   181.843
_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
  Er  Er0  1  0.689  0.311  0.500  1.0
  Er  Er1  1  0.311  0.689  0.500  1.0
  Zr  Zr2  1  0.744  0.744  0.896  1.0
  Zr  Zr3  1  0.256  0.256  0.104  1.0
  O  O4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.945  0.594  0.696  1.0
  O  O6  1  0.557  0.557  0.233  1.0
  O  O7  1  0.594  0.945  0.696  1.0
  O  O8  1  0.406  0.055  0.304  1.0
  O  O9  1  0.443  0.443  0.767  1.0
  O  O10  1  0.055  0.406  0.304  1.0
[/CIF]
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The compound described by Er2Zr2O7 crystallizes in the monoclinic C2/m space group. Er(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted ErO6 pentagonal pyramids that share corners with four equivalent Zr(1)O5 trigonal bipyramids, edges with three equivalent Er(1)O6 pentagonal pyramids, and edges with two equivalent Zr(1)O5 trigonal bipyramids. Zr(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted ZrO5 trigonal bipyramids that share corners with four equivalent Er(1)O6 pentagonal pyramids,  a cornercorner with one Zr(1)O5 trigonal bipyramid, edges with two equivalent Er(1)O6 pentagonal pyramids, and  an edgeedge with one Zr(1)O5 trigonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Zr(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Zr(1) atom. In the third O site, O(3) is bonded to two equivalent Er(1) and two equivalent Zr(1) atoms to form edge-sharing OEr2Zr2 trigonal pyramids. is represented by the CIF file [CIF]
data_Er2Zr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.880
_cell_length_b   5.880
_cell_length_c   5.614
_cell_angle_alpha   83.876
_cell_angle_beta   83.876
_cell_angle_gamma   107.693
_symmetry_Int_Tables_number   1
_cell_volume   181.843
_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
  Er  Er0  1  0.689  0.311  0.500  1.0
  Er  Er1  1  0.311  0.689  0.500  1.0
  Zr  Zr2  1  0.744  0.744  0.896  1.0
  Zr  Zr3  1  0.256  0.256  0.104  1.0
  O  O4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.945  0.594  0.696  1.0
  O  O6  1  0.557  0.557  0.233  1.0
  O  O7  1  0.594  0.945  0.696  1.0
  O  O8  1  0.406  0.055  0.304  1.0
  O  O9  1  0.443  0.443  0.767  1.0
  O  O10  1  0.055  0.406  0.304  1.0
[/CIF]
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