The compound described by Tl(Gd2Sr2)Ni2O9 crystallizes in the orthorhombic Fmm2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(4) atoms. Gd(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Ni(1) is bonded to one O(2), one O(4), and four equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and  a cornercorner with one Tl(1)O5 square pyramid. The corner-sharing octahedral tilt angles are 5°. Tl(1) is bonded to two equivalent O(4) and three equivalent O(3) atoms to form distorted TlO5 square pyramids that share corners with two equivalent Ni(1)O6 octahedra and corners with six equivalent Tl(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 7°. There are four inequivalent O sites. In the first O site, O(2) is bonded in a 6-coordinate geometry to five equivalent Gd(1) and one Ni(1) atom. In the second O site, O(3) is bonded to two equivalent Sr(1) and three equivalent Tl(1) atoms to form OSr2Tl3 square pyramids that share corners with two equivalent O(4)Sr4TlNi octahedra, corners with eight equivalent O(1)Sr2Gd2Ni2 octahedra, corners with six equivalent O(3)Sr2Tl3 square pyramids, and edges with six equivalent O(4)Sr4TlNi octahedra. The corner-sharing octahedral tilt angles range from 42-95°. In the third O site, O(4) is bonded to four equivalent Sr(1), one Ni(1), and one Tl(1) atom to form distorted OSr4TlNi octahedra that share corners with five equivalent O(4)Sr4TlNi octahedra, corners with eight equivalent O(1)Sr2Gd2Ni2 octahedra,  a cornercorner with one O(3)Sr2Tl3 square pyramid, edges with four equivalent O(4)Sr4TlNi octahedra, edges with three equivalent O(3)Sr2Tl3 square pyramids, and faces with four equivalent O(1)Sr2Gd2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 13-54°. In the fourth O site, O(1) is bonded to two equivalent Sr(1), two equivalent Gd(1), and two equivalent Ni(1) atoms to form distorted OSr2Gd2Ni2 octahedra that share corners with two equivalent O(1)Sr2Gd2Ni2 octahedra, corners with four equivalent O(4)Sr4TlNi octahedra, corners with two equivalent O(3)Sr2Tl3 square pyramids, edges with two equivalent O(1)Sr2Gd2Ni2 octahedra, faces with two equivalent O(4)Sr4TlNi octahedra, and faces with four equivalent O(1)Sr2Gd2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 5-54°. is represented by the CIF card [CIF]
data_Sr2Gd2TlNi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.033
_cell_length_b   15.029
_cell_length_c   3.811
_cell_angle_alpha   82.777
_cell_angle_beta   82.656
_cell_angle_gamma   14.568
_symmetry_Int_Tables_number   1
_cell_volume   214.787
_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
  Sr  Sr0  1  0.592  0.579  0.421  1.0
  Sr  Sr1  1  0.421  0.408  0.592  1.0
  Gd  Gd2  1  0.704  0.703  0.297  1.0
  Gd  Gd3  1  0.297  0.296  0.704  1.0
  Tl  Tl4  1  0.044  0.956  0.044  1.0
  Ni  Ni5  1  0.150  0.147  0.853  1.0
  Ni  Ni6  1  0.853  0.850  0.150  1.0
  O  O7  1  0.653  0.649  0.850  1.0
  O  O8  1  0.153  0.150  0.351  1.0
  O  O9  1  0.351  0.347  0.153  1.0
  O  O10  1  0.850  0.847  0.653  1.0
  O  O11  1  0.221  0.221  0.779  1.0
  O  O12  1  0.779  0.779  0.221  1.0
  O  O13  1  0.479  0.521  0.479  1.0
  O  O14  1  0.071  0.072  0.928  1.0
  O  O15  1  0.928  0.929  0.071  1.0
[/CIF]
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The compound described by Tl(Gd2Sr2)Ni2O9 crystallizes in the orthorhombic Fmm2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(4) atoms. Gd(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Ni(1) is bonded to one O(2), one O(4), and four equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and  a cornercorner with one Tl(1)O5 square pyramid. The corner-sharing octahedral tilt angles are 5°. Tl(1) is bonded to two equivalent O(4) and three equivalent O(3) atoms to form distorted TlO5 square pyramids that share corners with two equivalent Ni(1)O6 octahedra and corners with six equivalent Tl(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 7°. There are four inequivalent O sites. In the first O site, O(2) is bonded in a 6-coordinate geometry to five equivalent Gd(1) and one Ni(1) atom. In the second O site, O(3) is bonded to two equivalent Sr(1) and three equivalent Tl(1) atoms to form OSr2Tl3 square pyramids that share corners with two equivalent O(4)Sr4TlNi octahedra, corners with eight equivalent O(1)Sr2Gd2Ni2 octahedra, corners with six equivalent O(3)Sr2Tl3 square pyramids, and edges with six equivalent O(4)Sr4TlNi octahedra. The corner-sharing octahedral tilt angles range from 42-95°. In the third O site, O(4) is bonded to four equivalent Sr(1), one Ni(1), and one Tl(1) atom to form distorted OSr4TlNi octahedra that share corners with five equivalent O(4)Sr4TlNi octahedra, corners with eight equivalent O(1)Sr2Gd2Ni2 octahedra,  a cornercorner with one O(3)Sr2Tl3 square pyramid, edges with four equivalent O(4)Sr4TlNi octahedra, edges with three equivalent O(3)Sr2Tl3 square pyramids, and faces with four equivalent O(1)Sr2Gd2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 13-54°. In the fourth O site, O(1) is bonded to two equivalent Sr(1), two equivalent Gd(1), and two equivalent Ni(1) atoms to form distorted OSr2Gd2Ni2 octahedra that share corners with two equivalent O(1)Sr2Gd2Ni2 octahedra, corners with four equivalent O(4)Sr4TlNi octahedra, corners with two equivalent O(3)Sr2Tl3 square pyramids, edges with two equivalent O(1)Sr2Gd2Ni2 octahedra, faces with two equivalent O(4)Sr4TlNi octahedra, and faces with four equivalent O(1)Sr2Gd2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 5-54°. is represented by the CIF card [CIF]
data_Sr2Gd2TlNi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.033
_cell_length_b   15.029
_cell_length_c   3.811
_cell_angle_alpha   82.777
_cell_angle_beta   82.656
_cell_angle_gamma   14.568
_symmetry_Int_Tables_number   1
_cell_volume   214.787
_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
  Sr  Sr0  1  0.592  0.579  0.421  1.0
  Sr  Sr1  1  0.421  0.408  0.592  1.0
  Gd  Gd2  1  0.704  0.703  0.297  1.0
  Gd  Gd3  1  0.297  0.296  0.704  1.0
  Tl  Tl4  1  0.044  0.956  0.044  1.0
  Ni  Ni5  1  0.150  0.147  0.853  1.0
  Ni  Ni6  1  0.853  0.850  0.150  1.0
  O  O7  1  0.653  0.649  0.850  1.0
  O  O8  1  0.153  0.150  0.351  1.0
  O  O9  1  0.351  0.347  0.153  1.0
  O  O10  1  0.850  0.847  0.653  1.0
  O  O11  1  0.221  0.221  0.779  1.0
  O  O12  1  0.779  0.779  0.221  1.0
  O  O13  1  0.479  0.521  0.479  1.0
  O  O14  1  0.071  0.072  0.928  1.0
  O  O15  1  0.928  0.929  0.071  1.0
[/CIF]
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