The compound described by Tb2Pb2O7 crystallizes in the tetragonal P4_12_12 space group. Tb(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form distorted TbO7 pentagonal bipyramids that share corners with three equivalent Pb(1)O5 trigonal bipyramids, edges with five equivalent Tb(1)O7 pentagonal bipyramids, and edges with three equivalent Pb(1)O5 trigonal bipyramids. Pb(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted PbO5 trigonal bipyramids that share corners with three equivalent Tb(1)O7 pentagonal bipyramids,  a cornercorner with one Pb(1)O5 trigonal bipyramid, edges with three equivalent Tb(1)O7 pentagonal bipyramids, and  an edgeedge with one Pb(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Tb(1) and two equivalent Pb(1) atoms to form distorted OTb2Pb2 trigonal pyramids that share corners with two equivalent O(2)Tb3Pb tetrahedra, corners with two equivalent O(1)Tb2Pb2 trigonal pyramids, edges with three equivalent O(2)Tb3Pb tetrahedra, and  an edgeedge with one O(1)Tb2Pb2 trigonal pyramid. In the second O site, O(2) is bonded to three equivalent Tb(1) and one Pb(1) atom to form OTb3Pb tetrahedra that share corners with four equivalent O(2)Tb3Pb tetrahedra, corners with two equivalent O(1)Tb2Pb2 trigonal pyramids,  an edgeedge with one O(2)Tb3Pb tetrahedra, and edges with three equivalent O(1)Tb2Pb2 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Tb(1) and one Pb(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Pb(1) atoms. is represented by the CIF card [CIF]
data_Tb2Pb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.388
_cell_length_b   7.388
_cell_length_c   12.904
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   704.273
_cell_formula_units_Z   4
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
  Tb  Tb0  1  0.643  0.125  0.139  1.0
  Tb  Tb1  1  0.625  0.857  0.889  1.0
  Tb  Tb2  1  0.875  0.357  0.361  1.0
  Tb  Tb3  1  0.857  0.625  0.111  1.0
  Tb  Tb4  1  0.143  0.375  0.611  1.0
  Tb  Tb5  1  0.125  0.643  0.861  1.0
  Tb  Tb6  1  0.375  0.143  0.389  1.0
  Tb  Tb7  1  0.357  0.875  0.639  1.0
  Pb  Pb8  1  0.612  0.374  0.598  1.0
  Pb  Pb9  1  0.626  0.388  0.902  1.0
  Pb  Pb10  1  0.874  0.888  0.348  1.0
  Pb  Pb11  1  0.888  0.874  0.652  1.0
  Pb  Pb12  1  0.112  0.126  0.152  1.0
  Pb  Pb13  1  0.126  0.112  0.848  1.0
  Pb  Pb14  1  0.374  0.612  0.402  1.0
  Pb  Pb15  1  0.388  0.626  0.098  1.0
  O  O16  1  0.570  0.404  0.411  1.0
  O  O17  1  0.596  0.825  0.075  1.0
  O  O18  1  0.596  0.430  0.089  1.0
  O  O19  1  0.670  0.130  0.962  1.0
  O  O20  1  0.675  0.096  0.325  1.0
  O  O21  1  0.630  0.830  0.712  1.0
  O  O22  1  0.699  0.301  0.750  1.0
  O  O23  1  0.801  0.801  0.500  1.0
  O  O24  1  0.870  0.330  0.538  1.0
  O  O25  1  0.825  0.596  0.925  1.0
  O  O26  1  0.830  0.630  0.288  1.0
  O  O27  1  0.904  0.930  0.161  1.0
  O  O28  1  0.904  0.325  0.175  1.0
  O  O29  1  0.930  0.904  0.839  1.0
  O  O30  1  0.070  0.096  0.339  1.0
  O  O31  1  0.096  0.675  0.675  1.0
  O  O32  1  0.096  0.070  0.661  1.0
  O  O33  1  0.170  0.370  0.788  1.0
  O  O34  1  0.175  0.404  0.425  1.0
  O  O35  1  0.130  0.670  0.038  1.0
  O  O36  1  0.199  0.199  0.000  1.0
  O  O37  1  0.301  0.699  0.250  1.0
  O  O38  1  0.370  0.170  0.212  1.0
  O  O39  1  0.325  0.904  0.825  1.0
  O  O40  1  0.330  0.870  0.462  1.0
  O  O41  1  0.404  0.570  0.589  1.0
  O  O42  1  0.404  0.175  0.575  1.0
  O  O43  1  0.430  0.596  0.911  1.0
[/CIF]
.
The compound described by Tb2Pb2O7 crystallizes in the tetragonal P4_12_12 space group. Tb(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form distorted TbO7 pentagonal bipyramids that share corners with three equivalent Pb(1)O5 trigonal bipyramids, edges with five equivalent Tb(1)O7 pentagonal bipyramids, and edges with three equivalent Pb(1)O5 trigonal bipyramids. Pb(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted PbO5 trigonal bipyramids that share corners with three equivalent Tb(1)O7 pentagonal bipyramids,  a cornercorner with one Pb(1)O5 trigonal bipyramid, edges with three equivalent Tb(1)O7 pentagonal bipyramids, and  an edgeedge with one Pb(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Tb(1) and two equivalent Pb(1) atoms to form distorted OTb2Pb2 trigonal pyramids that share corners with two equivalent O(2)Tb3Pb tetrahedra, corners with two equivalent O(1)Tb2Pb2 trigonal pyramids, edges with three equivalent O(2)Tb3Pb tetrahedra, and  an edgeedge with one O(1)Tb2Pb2 trigonal pyramid. In the second O site, O(2) is bonded to three equivalent Tb(1) and one Pb(1) atom to form OTb3Pb tetrahedra that share corners with four equivalent O(2)Tb3Pb tetrahedra, corners with two equivalent O(1)Tb2Pb2 trigonal pyramids,  an edgeedge with one O(2)Tb3Pb tetrahedra, and edges with three equivalent O(1)Tb2Pb2 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Tb(1) and one Pb(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Pb(1) atoms. is represented by the CIF card [CIF]
data_Tb2Pb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.388
_cell_length_b   7.388
_cell_length_c   12.904
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   704.273
_cell_formula_units_Z   4
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
  Tb  Tb0  1  0.643  0.125  0.139  1.0
  Tb  Tb1  1  0.625  0.857  0.889  1.0
  Tb  Tb2  1  0.875  0.357  0.361  1.0
  Tb  Tb3  1  0.857  0.625  0.111  1.0
  Tb  Tb4  1  0.143  0.375  0.611  1.0
  Tb  Tb5  1  0.125  0.643  0.861  1.0
  Tb  Tb6  1  0.375  0.143  0.389  1.0
  Tb  Tb7  1  0.357  0.875  0.639  1.0
  Pb  Pb8  1  0.612  0.374  0.598  1.0
  Pb  Pb9  1  0.626  0.388  0.902  1.0
  Pb  Pb10  1  0.874  0.888  0.348  1.0
  Pb  Pb11  1  0.888  0.874  0.652  1.0
  Pb  Pb12  1  0.112  0.126  0.152  1.0
  Pb  Pb13  1  0.126  0.112  0.848  1.0
  Pb  Pb14  1  0.374  0.612  0.402  1.0
  Pb  Pb15  1  0.388  0.626  0.098  1.0
  O  O16  1  0.570  0.404  0.411  1.0
  O  O17  1  0.596  0.825  0.075  1.0
  O  O18  1  0.596  0.430  0.089  1.0
  O  O19  1  0.670  0.130  0.962  1.0
  O  O20  1  0.675  0.096  0.325  1.0
  O  O21  1  0.630  0.830  0.712  1.0
  O  O22  1  0.699  0.301  0.750  1.0
  O  O23  1  0.801  0.801  0.500  1.0
  O  O24  1  0.870  0.330  0.538  1.0
  O  O25  1  0.825  0.596  0.925  1.0
  O  O26  1  0.830  0.630  0.288  1.0
  O  O27  1  0.904  0.930  0.161  1.0
  O  O28  1  0.904  0.325  0.175  1.0
  O  O29  1  0.930  0.904  0.839  1.0
  O  O30  1  0.070  0.096  0.339  1.0
  O  O31  1  0.096  0.675  0.675  1.0
  O  O32  1  0.096  0.070  0.661  1.0
  O  O33  1  0.170  0.370  0.788  1.0
  O  O34  1  0.175  0.404  0.425  1.0
  O  O35  1  0.130  0.670  0.038  1.0
  O  O36  1  0.199  0.199  0.000  1.0
  O  O37  1  0.301  0.699  0.250  1.0
  O  O38  1  0.370  0.170  0.212  1.0
  O  O39  1  0.325  0.904  0.825  1.0
  O  O40  1  0.330  0.870  0.462  1.0
  O  O41  1  0.404  0.570  0.589  1.0
  O  O42  1  0.404  0.175  0.575  1.0
  O  O43  1  0.430  0.596  0.911  1.0
[/CIF]
.