The material structure described by GdCe4O9 crystallizes in the triclinic P1 space group. Gd(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(6), one O(7), and two equivalent O(8) atoms. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one O(1), one O(4), one O(8), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. In the second Ce site, Ce(2) is bonded in a body-centered cubic geometry to one O(1), one O(4), one O(6), one O(7), two equivalent O(5), and two equivalent O(9) atoms. In the third Ce site, Ce(3) is bonded in a body-centered cubic geometry to one O(2), one O(3), one O(5), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the fourth Ce site, Ce(4) is bonded to one O(5), one O(8), one O(9), two equivalent O(6), and two equivalent O(7) atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(7)Ce3Gd tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce4 tetrahedra, corners with four equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(5)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, edges with two equivalent O(4)Ce4 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(2)Ce3Gd trigonal pyramids. In the second O site, O(2) is bonded to one Gd(1), one Ce(3), and two equivalent Ce(1) atoms to form distorted OCe3Gd trigonal pyramids that share  a cornercorner with one O(7)Ce3Gd tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(4)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with two equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third O site, O(3) is bonded to one Gd(1), one Ce(3), and two equivalent Ce(1) atoms to form OCe3Gd tetrahedra that share  a cornercorner with one O(7)Ce3Gd tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(1)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with two equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(8)Ce2Gd2 tetrahedra, edges with two equivalent O(4)Ce4 tetrahedra, and edges with two equivalent O(2)Ce3Gd trigonal pyramids. In the fourth O site, O(4) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(7)Ce3Gd tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce4 tetrahedra, corners with four equivalent O(9)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with four equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, edges with two equivalent O(1)Ce4 tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. In the fifth O site, O(5) is bonded to one Ce(3), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(3)Ce3Gd tetrahedra, corners with two equivalent O(5)Ce4 tetrahedra, corners with two equivalent O(9)Ce4 tetrahedra, corners with four equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(1)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, edges with two equivalent O(4)Ce4 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(6)Ce3Gd trigonal pyramids. In the sixth O site, O(6) is bonded to one Gd(1), one Ce(2), and two equivalent Ce(4) atoms to form distorted OCe3Gd trigonal pyramids that share  a cornercorner with one O(3)Ce3Gd tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra, corners with two equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(9)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with two equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(7)Ce3Gd tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. In the seventh O site, O(7) is bonded to one Gd(1), one Ce(2), and two equivalent Ce(4) atoms to form OCe3Gd tetrahedra that share  a cornercorner with one O(3)Ce3Gd tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra, corners with two equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(5)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with two equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(8)Ce2Gd2 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(6)Ce3Gd trigonal pyramids. In the eighth O site, O(8) is bonded to two equivalent Gd(1), one Ce(1), and one Ce(4) atom to form OCe2Gd2 tetrahedra that share  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(2)Ce3Gd trigonal pyramids, corners with four equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, and edges with two equivalent O(7)Ce3Gd tetrahedra. In the ninth O site, O(9) is bonded to one Ce(3), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(3)Ce3Gd tetrahedra, corners with two equivalent O(5)Ce4 tetrahedra, corners with two equivalent O(9)Ce4 tetrahedra, corners with four equivalent O(4)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with four equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(7)Ce3Gd tetrahedra, edges with two equivalent O(1)Ce4 tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. is represented by the CIF card [CIF]
data_Ce4GdO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.815
_cell_length_b   10.369
_cell_length_c   5.535
_cell_angle_alpha   105.432
_cell_angle_beta   89.966
_cell_angle_gamma   79.377
_symmetry_Int_Tables_number   1
_cell_volume   207.123
_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
  Ce  Ce0  1  0.610  0.787  0.406  1.0
  Ce  Ce1  1  0.804  0.397  0.205  1.0
  Ce  Ce2  1  0.199  0.602  0.806  1.0
  Ce  Ce3  1  0.399  0.213  0.619  1.0
  Gd  Gd4  1  0.005  0.000  0.952  1.0
  O  O5  1  0.698  0.607  0.060  1.0
  O  O6  1  0.086  0.834  0.176  1.0
  O  O7  1  0.107  0.791  0.648  1.0
  O  O8  1  0.704  0.595  0.552  1.0
  O  O9  1  0.304  0.393  0.457  1.0
  O  O10  1  0.922  0.169  0.338  1.0
  O  O11  1  0.901  0.209  0.853  1.0
  O  O12  1  0.505  0.000  0.734  1.0
  O  O13  1  0.302  0.404  0.961  1.0
[/CIF]
.
The material structure described by GdCe4O9 crystallizes in the triclinic P1 space group. Gd(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(6), one O(7), and two equivalent O(8) atoms. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one O(1), one O(4), one O(8), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. In the second Ce site, Ce(2) is bonded in a body-centered cubic geometry to one O(1), one O(4), one O(6), one O(7), two equivalent O(5), and two equivalent O(9) atoms. In the third Ce site, Ce(3) is bonded in a body-centered cubic geometry to one O(2), one O(3), one O(5), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the fourth Ce site, Ce(4) is bonded to one O(5), one O(8), one O(9), two equivalent O(6), and two equivalent O(7) atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(7)Ce3Gd tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce4 tetrahedra, corners with four equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(5)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, edges with two equivalent O(4)Ce4 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(2)Ce3Gd trigonal pyramids. In the second O site, O(2) is bonded to one Gd(1), one Ce(3), and two equivalent Ce(1) atoms to form distorted OCe3Gd trigonal pyramids that share  a cornercorner with one O(7)Ce3Gd tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(4)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with two equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third O site, O(3) is bonded to one Gd(1), one Ce(3), and two equivalent Ce(1) atoms to form OCe3Gd tetrahedra that share  a cornercorner with one O(7)Ce3Gd tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Gd tetrahedra, corners with four equivalent O(1)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with two equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(8)Ce2Gd2 tetrahedra, edges with two equivalent O(4)Ce4 tetrahedra, and edges with two equivalent O(2)Ce3Gd trigonal pyramids. In the fourth O site, O(4) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(7)Ce3Gd tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce4 tetrahedra, corners with four equivalent O(9)Ce4 tetrahedra,  a cornercorner with one O(6)Ce3Gd trigonal pyramid, corners with four equivalent O(2)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, edges with two equivalent O(1)Ce4 tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. In the fifth O site, O(5) is bonded to one Ce(3), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(3)Ce3Gd tetrahedra, corners with two equivalent O(5)Ce4 tetrahedra, corners with two equivalent O(9)Ce4 tetrahedra, corners with four equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(1)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, edges with two equivalent O(4)Ce4 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(6)Ce3Gd trigonal pyramids. In the sixth O site, O(6) is bonded to one Gd(1), one Ce(2), and two equivalent Ce(4) atoms to form distorted OCe3Gd trigonal pyramids that share  a cornercorner with one O(3)Ce3Gd tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra, corners with two equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(9)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with two equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(7)Ce3Gd tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. In the seventh O site, O(7) is bonded to one Gd(1), one Ce(2), and two equivalent Ce(4) atoms to form OCe3Gd tetrahedra that share  a cornercorner with one O(3)Ce3Gd tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra, corners with two equivalent O(7)Ce3Gd tetrahedra, corners with four equivalent O(5)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with two equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(8)Ce2Gd2 tetrahedra, edges with two equivalent O(9)Ce4 tetrahedra, and edges with two equivalent O(6)Ce3Gd trigonal pyramids. In the eighth O site, O(8) is bonded to two equivalent Gd(1), one Ce(1), and one Ce(4) atom to form OCe2Gd2 tetrahedra that share  a cornercorner with one O(1)Ce4 tetrahedra,  a cornercorner with one O(4)Ce4 tetrahedra,  a cornercorner with one O(5)Ce4 tetrahedra,  a cornercorner with one O(9)Ce4 tetrahedra, corners with two equivalent O(8)Ce2Gd2 tetrahedra, corners with four equivalent O(2)Ce3Gd trigonal pyramids, corners with four equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(3)Ce3Gd tetrahedra, and edges with two equivalent O(7)Ce3Gd tetrahedra. In the ninth O site, O(9) is bonded to one Ce(3), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(8)Ce2Gd2 tetrahedra,  a cornercorner with one O(3)Ce3Gd tetrahedra, corners with two equivalent O(5)Ce4 tetrahedra, corners with two equivalent O(9)Ce4 tetrahedra, corners with four equivalent O(4)Ce4 tetrahedra,  a cornercorner with one O(2)Ce3Gd trigonal pyramid, corners with four equivalent O(6)Ce3Gd trigonal pyramids, edges with two equivalent O(7)Ce3Gd tetrahedra, edges with two equivalent O(1)Ce4 tetrahedra, and edges with two equivalent O(5)Ce4 tetrahedra. is represented by the CIF card [CIF]
data_Ce4GdO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.815
_cell_length_b   10.369
_cell_length_c   5.535
_cell_angle_alpha   105.432
_cell_angle_beta   89.966
_cell_angle_gamma   79.377
_symmetry_Int_Tables_number   1
_cell_volume   207.123
_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
  Ce  Ce0  1  0.610  0.787  0.406  1.0
  Ce  Ce1  1  0.804  0.397  0.205  1.0
  Ce  Ce2  1  0.199  0.602  0.806  1.0
  Ce  Ce3  1  0.399  0.213  0.619  1.0
  Gd  Gd4  1  0.005  0.000  0.952  1.0
  O  O5  1  0.698  0.607  0.060  1.0
  O  O6  1  0.086  0.834  0.176  1.0
  O  O7  1  0.107  0.791  0.648  1.0
  O  O8  1  0.704  0.595  0.552  1.0
  O  O9  1  0.304  0.393  0.457  1.0
  O  O10  1  0.922  0.169  0.338  1.0
  O  O11  1  0.901  0.209  0.853  1.0
  O  O12  1  0.505  0.000  0.734  1.0
  O  O13  1  0.302  0.404  0.961  1.0
[/CIF]
.