The structure described by YZr4O9 crystallizes in the triclinic P1 space group. Y(1) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form distorted YO7 pentagonal bipyramids that share  a cornercorner with one Zr(2)O7 pentagonal bipyramid,  a cornercorner with one Zr(3)O7 pentagonal bipyramid, edges with two equivalent Zr(2)O7 pentagonal bipyramids, and edges with two equivalent Zr(3)O7 pentagonal bipyramids. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second Zr site, Zr(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom to form distorted ZrO7 pentagonal bipyramids that share  a cornercorner with one Y(1)O7 pentagonal bipyramid,  a cornercorner with one Zr(3)O7 pentagonal bipyramid, edges with two equivalent Y(1)O7 pentagonal bipyramids, and edges with two equivalent Zr(3)O7 pentagonal bipyramids. In the third Zr site, Zr(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom to form distorted ZrO7 pentagonal bipyramids that share  a cornercorner with one Y(1)O7 pentagonal bipyramid,  a cornercorner with one Zr(2)O7 pentagonal bipyramid, edges with two equivalent Y(1)O7 pentagonal bipyramids, and edges with two equivalent Zr(2)O7 pentagonal bipyramids. In the fourth Zr site, Zr(4) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Zr(1), one Zr(2), and one Zr(3) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra, and  an edgeedge with one O(4)Zr4 tetrahedra. In the second O site, O(2) is bonded to one Y(1), one Zr(1), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, edges with two equivalent O(7)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the third O site, O(3) is bonded to one Y(1), one Zr(1), one Zr(2), and one Zr(4) atom to form distorted OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the fourth O site, O(4) is bonded to one Zr(1), one Zr(2), one Zr(3), and one Zr(4) atom to form distorted OZr4 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, and edges with two equivalent O(5)Zr4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Zr(1), one Zr(2), one Zr(3), and one Zr(4) atom to form distorted OZr4 trigonal pyramids that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Y(1), one Zr(1), and one Zr(2) atom. In the seventh O site, O(7) is bonded to one Y(1), one Zr(1), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(2)YZr3 tetrahedra. In the eighth O site, O(8) is bonded to one Y(1), one Zr(2), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra, edges with two equivalent O(9)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the ninth O site, O(9) is bonded to one Y(1), one Zr(2), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(8)YZr3 tetrahedra. is represented by the CIF card [CIF]
data_YZr4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.254
_cell_length_b   6.168
_cell_length_c   6.358
_cell_angle_alpha   80.718
_cell_angle_beta   68.932
_cell_angle_gamma   67.641
_symmetry_Int_Tables_number   1
_cell_volume   177.760
_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  0.187  0.367  0.209  1.0
  Zr  Zr1  1  0.432  0.799  0.421  1.0
  Zr  Zr2  1  0.942  0.028  0.004  1.0
  Zr  Zr3  1  0.835  0.612  0.760  1.0
  Zr  Zr4  1  0.548  0.216  0.638  1.0
  O  O5  1  0.835  0.712  0.090  1.0
  O  O6  1  0.759  0.464  0.499  1.0
  O  O7  1  0.583  0.106  0.328  1.0
  O  O8  1  0.929  0.950  0.686  1.0
  O  O9  1  0.427  0.867  0.748  1.0
  O  O10  1  0.183  0.995  0.217  1.0
  O  O11  1  0.241  0.533  0.489  1.0
  O  O12  1  0.136  0.305  0.878  1.0
  O  O13  1  0.612  0.346  0.931  1.0
[/CIF]
.
The structure described by YZr4O9 crystallizes in the triclinic P1 space group. Y(1) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form distorted YO7 pentagonal bipyramids that share  a cornercorner with one Zr(2)O7 pentagonal bipyramid,  a cornercorner with one Zr(3)O7 pentagonal bipyramid, edges with two equivalent Zr(2)O7 pentagonal bipyramids, and edges with two equivalent Zr(3)O7 pentagonal bipyramids. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second Zr site, Zr(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), one O(8), and one O(9) atom to form distorted ZrO7 pentagonal bipyramids that share  a cornercorner with one Y(1)O7 pentagonal bipyramid,  a cornercorner with one Zr(3)O7 pentagonal bipyramid, edges with two equivalent Y(1)O7 pentagonal bipyramids, and edges with two equivalent Zr(3)O7 pentagonal bipyramids. In the third Zr site, Zr(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom to form distorted ZrO7 pentagonal bipyramids that share  a cornercorner with one Y(1)O7 pentagonal bipyramid,  a cornercorner with one Zr(2)O7 pentagonal bipyramid, edges with two equivalent Y(1)O7 pentagonal bipyramids, and edges with two equivalent Zr(2)O7 pentagonal bipyramids. In the fourth Zr site, Zr(4) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Zr(1), one Zr(2), and one Zr(3) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra, and  an edgeedge with one O(4)Zr4 tetrahedra. In the second O site, O(2) is bonded to one Y(1), one Zr(1), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, edges with two equivalent O(7)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the third O site, O(3) is bonded to one Y(1), one Zr(1), one Zr(2), and one Zr(4) atom to form distorted OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the fourth O site, O(4) is bonded to one Zr(1), one Zr(2), one Zr(3), and one Zr(4) atom to form distorted OZr4 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra,  a cornercorner with one O(9)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(8)YZr3 tetrahedra,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra,  an edgeedge with one O(9)YZr3 tetrahedra, and edges with two equivalent O(5)Zr4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Zr(1), one Zr(2), one Zr(3), and one Zr(4) atom to form distorted OZr4 trigonal pyramids that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Y(1), one Zr(1), and one Zr(2) atom. In the seventh O site, O(7) is bonded to one Y(1), one Zr(1), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(8)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(9)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(8)YZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(2)YZr3 tetrahedra. In the eighth O site, O(8) is bonded to one Y(1), one Zr(2), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(1)YZr3 tetrahedra,  a cornercorner with one O(7)YZr3 tetrahedra, corners with three equivalent O(2)YZr3 tetrahedra, corners with three equivalent O(3)YZr3 tetrahedra, corners with three equivalent O(4)Zr4 tetrahedra,  a cornercorner with one O(5)Zr4 trigonal pyramid,  an edgeedge with one O(1)YZr3 tetrahedra,  an edgeedge with one O(7)YZr3 tetrahedra, edges with two equivalent O(9)YZr3 tetrahedra, and  an edgeedge with one O(5)Zr4 trigonal pyramid. In the ninth O site, O(9) is bonded to one Y(1), one Zr(2), one Zr(3), and one Zr(4) atom to form OYZr3 tetrahedra that share  a cornercorner with one O(2)YZr3 tetrahedra,  a cornercorner with one O(3)YZr3 tetrahedra,  a cornercorner with one O(4)Zr4 tetrahedra, corners with three equivalent O(1)YZr3 tetrahedra, corners with three equivalent O(7)YZr3 tetrahedra, corners with three equivalent O(5)Zr4 trigonal pyramids,  an edgeedge with one O(2)YZr3 tetrahedra,  an edgeedge with one O(3)YZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(8)YZr3 tetrahedra. is represented by the CIF card [CIF]
data_YZr4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.254
_cell_length_b   6.168
_cell_length_c   6.358
_cell_angle_alpha   80.718
_cell_angle_beta   68.932
_cell_angle_gamma   67.641
_symmetry_Int_Tables_number   1
_cell_volume   177.760
_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  0.187  0.367  0.209  1.0
  Zr  Zr1  1  0.432  0.799  0.421  1.0
  Zr  Zr2  1  0.942  0.028  0.004  1.0
  Zr  Zr3  1  0.835  0.612  0.760  1.0
  Zr  Zr4  1  0.548  0.216  0.638  1.0
  O  O5  1  0.835  0.712  0.090  1.0
  O  O6  1  0.759  0.464  0.499  1.0
  O  O7  1  0.583  0.106  0.328  1.0
  O  O8  1  0.929  0.950  0.686  1.0
  O  O9  1  0.427  0.867  0.748  1.0
  O  O10  1  0.183  0.995  0.217  1.0
  O  O11  1  0.241  0.533  0.489  1.0
  O  O12  1  0.136  0.305  0.878  1.0
  O  O13  1  0.612  0.346  0.931  1.0
[/CIF]
.