The compound described by TiNb6Tl2O18 crystallizes in the monoclinic C2 space group. Ti(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-36°. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(9), and two equivalent O(8) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-50°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), one O(5), one O(9), and two equivalent O(7) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-49°. In the third Nb site, Nb(3) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-50°. Tl(1) is bonded in a single-bond geometry to one O(8) atom. There are nine inequivalent O sites. In the first O site, O(9) is bonded in a trigonal non-coplanar geometry to one Nb(1), one Nb(2), and one Nb(3) atom. In the second O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(2) and one Nb(3) atom. In the third O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(3) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(2) atom. In the fifth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(1) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(2) atom. In the seventh O site, O(6) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(3) atom. In the eighth O site, O(7) is bonded in a trigonal non-coplanar geometry to one Nb(3) and two equivalent Nb(2) atoms. In the ninth O site, O(8) is bonded to one Nb(3), two equivalent Nb(1), and one Tl(1) atom to form distorted edge-sharing ONb3Tl tetrahedra. is represented by the CIF card [CIF]
data_TiNb6Tl2O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.692
_cell_length_b   7.692
_cell_length_c   8.300
_cell_angle_alpha   89.865
_cell_angle_beta   89.865
_cell_angle_gamma   59.949
_symmetry_Int_Tables_number   1
_cell_volume   425.099
_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
  Ti  Ti0  1  0.998  0.002  0.500  1.0
  Nb  Nb1  1  0.334  0.836  0.847  1.0
  Nb  Nb2  1  0.831  0.338  0.848  1.0
  Nb  Nb3  1  0.829  0.836  0.848  1.0
  Nb  Nb4  1  0.662  0.169  0.152  1.0
  Nb  Nb5  1  0.164  0.666  0.153  1.0
  Nb  Nb6  1  0.164  0.171  0.152  1.0
  Tl  Tl7  1  0.625  0.688  0.297  1.0
  Tl  Tl8  1  0.312  0.375  0.703  1.0
  O  O9  1  0.897  0.552  0.838  1.0
  O  O10  1  0.552  0.896  0.839  1.0
  O  O11  1  0.551  0.553  0.838  1.0
  O  O12  1  0.104  0.448  0.161  1.0
  O  O13  1  0.448  0.103  0.162  1.0
  O  O14  1  0.447  0.449  0.162  1.0
  O  O15  1  0.241  0.878  0.636  1.0
  O  O16  1  0.880  0.240  0.637  1.0
  O  O17  1  0.881  0.879  0.637  1.0
  O  O18  1  0.760  0.120  0.363  1.0
  O  O19  1  0.122  0.759  0.364  1.0
  O  O20  1  0.121  0.119  0.363  1.0
  O  O21  1  0.715  0.143  0.898  1.0
  O  O22  1  0.143  0.715  0.897  1.0
  O  O23  1  0.142  0.142  0.897  1.0
  O  O24  1  0.285  0.857  0.103  1.0
  O  O25  1  0.857  0.285  0.102  1.0
  O  O26  1  0.858  0.858  0.103  1.0
[/CIF]
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The compound described by TiNb6Tl2O18 crystallizes in the monoclinic C2 space group. Ti(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-36°. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(9), and two equivalent O(8) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-50°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), one O(5), one O(9), and two equivalent O(7) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-49°. In the third Nb site, Nb(3) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-50°. Tl(1) is bonded in a single-bond geometry to one O(8) atom. There are nine inequivalent O sites. In the first O site, O(9) is bonded in a trigonal non-coplanar geometry to one Nb(1), one Nb(2), and one Nb(3) atom. In the second O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(2) and one Nb(3) atom. In the third O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(3) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(2) atom. In the fifth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(1) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(2) atom. In the seventh O site, O(6) is bonded in a bent 150 degrees geometry to one Ti(1) and one Nb(3) atom. In the eighth O site, O(7) is bonded in a trigonal non-coplanar geometry to one Nb(3) and two equivalent Nb(2) atoms. In the ninth O site, O(8) is bonded to one Nb(3), two equivalent Nb(1), and one Tl(1) atom to form distorted edge-sharing ONb3Tl tetrahedra. is represented by the CIF card [CIF]
data_TiNb6Tl2O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.692
_cell_length_b   7.692
_cell_length_c   8.300
_cell_angle_alpha   89.865
_cell_angle_beta   89.865
_cell_angle_gamma   59.949
_symmetry_Int_Tables_number   1
_cell_volume   425.099
_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
  Ti  Ti0  1  0.998  0.002  0.500  1.0
  Nb  Nb1  1  0.334  0.836  0.847  1.0
  Nb  Nb2  1  0.831  0.338  0.848  1.0
  Nb  Nb3  1  0.829  0.836  0.848  1.0
  Nb  Nb4  1  0.662  0.169  0.152  1.0
  Nb  Nb5  1  0.164  0.666  0.153  1.0
  Nb  Nb6  1  0.164  0.171  0.152  1.0
  Tl  Tl7  1  0.625  0.688  0.297  1.0
  Tl  Tl8  1  0.312  0.375  0.703  1.0
  O  O9  1  0.897  0.552  0.838  1.0
  O  O10  1  0.552  0.896  0.839  1.0
  O  O11  1  0.551  0.553  0.838  1.0
  O  O12  1  0.104  0.448  0.161  1.0
  O  O13  1  0.448  0.103  0.162  1.0
  O  O14  1  0.447  0.449  0.162  1.0
  O  O15  1  0.241  0.878  0.636  1.0
  O  O16  1  0.880  0.240  0.637  1.0
  O  O17  1  0.881  0.879  0.637  1.0
  O  O18  1  0.760  0.120  0.363  1.0
  O  O19  1  0.122  0.759  0.364  1.0
  O  O20  1  0.121  0.119  0.363  1.0
  O  O21  1  0.715  0.143  0.898  1.0
  O  O22  1  0.143  0.715  0.897  1.0
  O  O23  1  0.142  0.142  0.897  1.0
  O  O24  1  0.285  0.857  0.103  1.0
  O  O25  1  0.857  0.285  0.102  1.0
  O  O26  1  0.858  0.858  0.103  1.0
[/CIF]
.