The structure described by Tm2Ti2O7 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(4), one O(9), two equivalent O(13), and two equivalent O(6) atoms. In the second Tm site, Tm(2) is bonded in a 7-coordinate geometry to one O(12), one O(3), one O(8), two equivalent O(2), and two equivalent O(5) atoms. In the third Tm site, Tm(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(13), one O(14), one O(6), one O(7), and one O(9) atom. In the fourth Tm site, Tm(4) is bonded in a 8-coordinate geometry to one O(10), one O(14), one O(2), one O(5), one O(7), one O(8), and two equivalent O(12) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one O(7) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. In the second Ti site, Ti(2) is bonded to one O(1), one O(11), one O(4), one O(7), and two equivalent O(6) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-47°. In the third Ti site, Ti(3) is bonded to one O(10), one O(12), one O(14), one O(3), one O(8), and one O(9) atom to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 34-52°. In the fourth Ti site, Ti(4) is bonded to one O(11), one O(14), one O(4), one O(9), and two equivalent O(13) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Tm(1), one Tm(3), one Ti(1), and one Ti(2) atom to form distorted OTm2Ti2 tetrahedra that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra,  a cornercorner with one O(2)Tm3Ti tetrahedra,  a cornercorner with one O(5)Tm3Ti tetrahedra, corners with two equivalent O(9)Tm2Ti2 tetrahedra,  an edgeedge with one O(11)Tm2Ti2 tetrahedra, and  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid. In the second O site, O(2) is bonded to one Tm(4), two equivalent Tm(2), and one Ti(1) atom to form distorted OTm3Ti tetrahedra that share  a cornercorner with one O(1)Tm2Ti2 tetrahedra, corners with two equivalent O(2)Tm3Ti tetrahedra, corners with two equivalent O(12)Tm3Ti trigonal pyramids, edges with three equivalent O(5)Tm3Ti tetrahedra,  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid, and  an edgeedge with one O(12)Tm3Ti trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Tm(2), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Tm(1), one Ti(2), and one Ti(4) atom. In the fifth O site, O(5) is bonded to one Tm(4), two equivalent Tm(2), and one Ti(1) atom to form distorted OTm3Ti tetrahedra that share  a cornercorner with one O(1)Tm2Ti2 tetrahedra, corners with two equivalent O(5)Tm3Ti tetrahedra, corners with two equivalent O(10)Tm2Ti2 trigonal pyramids, corners with four equivalent O(12)Tm3Ti trigonal pyramids, and edges with three equivalent O(2)Tm3Ti tetrahedra. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Tm(3), two equivalent Tm(1), and two equivalent Ti(2) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Tm(3), one Tm(4), one Ti(1), and one Ti(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Tm(2), one Tm(4), and one Ti(3) atom. In the ninth O site, O(9) is bonded to one Tm(1), one Tm(3), one Ti(3), and one Ti(4) atom to form distorted OTm2Ti2 tetrahedra that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra, corners with two equivalent O(1)Tm2Ti2 tetrahedra,  a cornercorner with one O(12)Tm3Ti trigonal pyramid,  an edgeedge with one O(11)Tm2Ti2 tetrahedra, and  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Tm(3), one Tm(4), one Ti(1), and one Ti(3) atom to form distorted OTm2Ti2 trigonal pyramids that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra, corners with two equivalent O(5)Tm3Ti tetrahedra, corners with three equivalent O(12)Tm3Ti trigonal pyramids,  an edgeedge with one O(1)Tm2Ti2 tetrahedra,  an edgeedge with one O(9)Tm2Ti2 tetrahedra, and  an edgeedge with one O(2)Tm3Ti tetrahedra. In the eleventh O site, O(11) is bonded to one Tm(1), one Tm(3), one Ti(2), and one Ti(4) atom to form a mixture of distorted edge and corner-sharing OTm2Ti2 tetrahedra. In the twelfth O site, O(12) is bonded to one Tm(2), two equivalent Tm(4), and one Ti(3) atom to form distorted OTm3Ti trigonal pyramids that share  a cornercorner with one O(9)Tm2Ti2 tetrahedra, corners with two equivalent O(2)Tm3Ti tetrahedra, corners with four equivalent O(5)Tm3Ti tetrahedra, corners with two equivalent O(12)Tm3Ti trigonal pyramids, corners with three equivalent O(10)Tm2Ti2 trigonal pyramids, and  an edgeedge with one O(2)Tm3Ti tetrahedra. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Tm(3), two equivalent Tm(1), and two equivalent Ti(4) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Tm(3), one Tm(4), one Ti(3), and one Ti(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tm2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.237
_cell_length_b   7.408
_cell_length_c   13.018
_cell_angle_alpha   81.665
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   499.686
_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
  Tm  Tm0  1  0.775  0.764  0.927  1.0
  Tm  Tm1  1  0.356  0.860  0.561  1.0
  Tm  Tm2  1  0.246  0.714  0.135  1.0
  Tm  Tm3  1  0.778  0.644  0.388  1.0
  Tm  Tm4  1  0.278  0.356  0.612  1.0
  Tm  Tm5  1  0.746  0.286  0.865  1.0
  Tm  Tm6  1  0.856  0.140  0.439  1.0
  Tm  Tm7  1  0.275  0.236  0.073  1.0
  Ti  Ti8  1  0.281  0.929  0.321  1.0
  Ti  Ti9  1  0.768  0.971  0.122  1.0
  Ti  Ti10  1  0.792  0.590  0.672  1.0
  Ti  Ti11  1  0.268  0.531  0.873  1.0
  Ti  Ti12  1  0.768  0.469  0.127  1.0
  Ti  Ti13  1  0.292  0.410  0.328  1.0
  Ti  Ti14  1  0.268  0.029  0.878  1.0
  Ti  Ti15  1  0.781  0.071  0.679  1.0
  O  O16  1  0.430  0.996  0.178  1.0
  O  O17  1  0.564  0.927  0.409  1.0
  O  O18  1  0.664  0.829  0.682  1.0
  O  O19  1  0.361  0.779  0.882  1.0
  O  O20  1  0.064  0.856  0.432  1.0
  O  O21  1  0.046  0.936  0.025  1.0
  O  O22  1  0.954  0.869  0.233  1.0
  O  O23  1  0.102  0.636  0.618  1.0
  O  O24  1  0.928  0.581  0.823  1.0
  O  O25  1  0.387  0.674  0.304  1.0
  O  O26  1  0.646  0.728  0.090  1.0
  O  O27  1  0.589  0.585  0.551  1.0
  O  O28  1  0.543  0.450  0.973  1.0
  O  O29  1  0.457  0.483  0.763  1.0
  O  O30  1  0.957  0.517  0.237  1.0
  O  O31  1  0.043  0.550  0.027  1.0
  O  O32  1  0.089  0.415  0.449  1.0
  O  O33  1  0.146  0.272  0.910  1.0
  O  O34  1  0.887  0.326  0.696  1.0
  O  O35  1  0.428  0.419  0.177  1.0
  O  O36  1  0.602  0.364  0.382  1.0
  O  O37  1  0.454  0.131  0.767  1.0
  O  O38  1  0.546  0.064  0.975  1.0
  O  O39  1  0.564  0.144  0.568  1.0
  O  O40  1  0.861  0.221  0.118  1.0
  O  O41  1  0.164  0.171  0.318  1.0
  O  O42  1  0.064  0.073  0.591  1.0
  O  O43  1  0.930  0.004  0.822  1.0
[/CIF]
.
The structure described by Tm2Ti2O7 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(4), one O(9), two equivalent O(13), and two equivalent O(6) atoms. In the second Tm site, Tm(2) is bonded in a 7-coordinate geometry to one O(12), one O(3), one O(8), two equivalent O(2), and two equivalent O(5) atoms. In the third Tm site, Tm(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(13), one O(14), one O(6), one O(7), and one O(9) atom. In the fourth Tm site, Tm(4) is bonded in a 8-coordinate geometry to one O(10), one O(14), one O(2), one O(5), one O(7), one O(8), and two equivalent O(12) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one O(7) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. In the second Ti site, Ti(2) is bonded to one O(1), one O(11), one O(4), one O(7), and two equivalent O(6) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-47°. In the third Ti site, Ti(3) is bonded to one O(10), one O(12), one O(14), one O(3), one O(8), and one O(9) atom to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 34-52°. In the fourth Ti site, Ti(4) is bonded to one O(11), one O(14), one O(4), one O(9), and two equivalent O(13) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Tm(1), one Tm(3), one Ti(1), and one Ti(2) atom to form distorted OTm2Ti2 tetrahedra that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra,  a cornercorner with one O(2)Tm3Ti tetrahedra,  a cornercorner with one O(5)Tm3Ti tetrahedra, corners with two equivalent O(9)Tm2Ti2 tetrahedra,  an edgeedge with one O(11)Tm2Ti2 tetrahedra, and  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid. In the second O site, O(2) is bonded to one Tm(4), two equivalent Tm(2), and one Ti(1) atom to form distorted OTm3Ti tetrahedra that share  a cornercorner with one O(1)Tm2Ti2 tetrahedra, corners with two equivalent O(2)Tm3Ti tetrahedra, corners with two equivalent O(12)Tm3Ti trigonal pyramids, edges with three equivalent O(5)Tm3Ti tetrahedra,  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid, and  an edgeedge with one O(12)Tm3Ti trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Tm(2), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Tm(1), one Ti(2), and one Ti(4) atom. In the fifth O site, O(5) is bonded to one Tm(4), two equivalent Tm(2), and one Ti(1) atom to form distorted OTm3Ti tetrahedra that share  a cornercorner with one O(1)Tm2Ti2 tetrahedra, corners with two equivalent O(5)Tm3Ti tetrahedra, corners with two equivalent O(10)Tm2Ti2 trigonal pyramids, corners with four equivalent O(12)Tm3Ti trigonal pyramids, and edges with three equivalent O(2)Tm3Ti tetrahedra. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Tm(3), two equivalent Tm(1), and two equivalent Ti(2) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Tm(3), one Tm(4), one Ti(1), and one Ti(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Tm(2), one Tm(4), and one Ti(3) atom. In the ninth O site, O(9) is bonded to one Tm(1), one Tm(3), one Ti(3), and one Ti(4) atom to form distorted OTm2Ti2 tetrahedra that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra, corners with two equivalent O(1)Tm2Ti2 tetrahedra,  a cornercorner with one O(12)Tm3Ti trigonal pyramid,  an edgeedge with one O(11)Tm2Ti2 tetrahedra, and  an edgeedge with one O(10)Tm2Ti2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Tm(3), one Tm(4), one Ti(1), and one Ti(3) atom to form distorted OTm2Ti2 trigonal pyramids that share  a cornercorner with one O(11)Tm2Ti2 tetrahedra, corners with two equivalent O(5)Tm3Ti tetrahedra, corners with three equivalent O(12)Tm3Ti trigonal pyramids,  an edgeedge with one O(1)Tm2Ti2 tetrahedra,  an edgeedge with one O(9)Tm2Ti2 tetrahedra, and  an edgeedge with one O(2)Tm3Ti tetrahedra. In the eleventh O site, O(11) is bonded to one Tm(1), one Tm(3), one Ti(2), and one Ti(4) atom to form a mixture of distorted edge and corner-sharing OTm2Ti2 tetrahedra. In the twelfth O site, O(12) is bonded to one Tm(2), two equivalent Tm(4), and one Ti(3) atom to form distorted OTm3Ti trigonal pyramids that share  a cornercorner with one O(9)Tm2Ti2 tetrahedra, corners with two equivalent O(2)Tm3Ti tetrahedra, corners with four equivalent O(5)Tm3Ti tetrahedra, corners with two equivalent O(12)Tm3Ti trigonal pyramids, corners with three equivalent O(10)Tm2Ti2 trigonal pyramids, and  an edgeedge with one O(2)Tm3Ti tetrahedra. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Tm(3), two equivalent Tm(1), and two equivalent Ti(4) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Tm(3), one Tm(4), one Ti(3), and one Ti(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tm2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.237
_cell_length_b   7.408
_cell_length_c   13.018
_cell_angle_alpha   81.665
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   499.686
_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
  Tm  Tm0  1  0.775  0.764  0.927  1.0
  Tm  Tm1  1  0.356  0.860  0.561  1.0
  Tm  Tm2  1  0.246  0.714  0.135  1.0
  Tm  Tm3  1  0.778  0.644  0.388  1.0
  Tm  Tm4  1  0.278  0.356  0.612  1.0
  Tm  Tm5  1  0.746  0.286  0.865  1.0
  Tm  Tm6  1  0.856  0.140  0.439  1.0
  Tm  Tm7  1  0.275  0.236  0.073  1.0
  Ti  Ti8  1  0.281  0.929  0.321  1.0
  Ti  Ti9  1  0.768  0.971  0.122  1.0
  Ti  Ti10  1  0.792  0.590  0.672  1.0
  Ti  Ti11  1  0.268  0.531  0.873  1.0
  Ti  Ti12  1  0.768  0.469  0.127  1.0
  Ti  Ti13  1  0.292  0.410  0.328  1.0
  Ti  Ti14  1  0.268  0.029  0.878  1.0
  Ti  Ti15  1  0.781  0.071  0.679  1.0
  O  O16  1  0.430  0.996  0.178  1.0
  O  O17  1  0.564  0.927  0.409  1.0
  O  O18  1  0.664  0.829  0.682  1.0
  O  O19  1  0.361  0.779  0.882  1.0
  O  O20  1  0.064  0.856  0.432  1.0
  O  O21  1  0.046  0.936  0.025  1.0
  O  O22  1  0.954  0.869  0.233  1.0
  O  O23  1  0.102  0.636  0.618  1.0
  O  O24  1  0.928  0.581  0.823  1.0
  O  O25  1  0.387  0.674  0.304  1.0
  O  O26  1  0.646  0.728  0.090  1.0
  O  O27  1  0.589  0.585  0.551  1.0
  O  O28  1  0.543  0.450  0.973  1.0
  O  O29  1  0.457  0.483  0.763  1.0
  O  O30  1  0.957  0.517  0.237  1.0
  O  O31  1  0.043  0.550  0.027  1.0
  O  O32  1  0.089  0.415  0.449  1.0
  O  O33  1  0.146  0.272  0.910  1.0
  O  O34  1  0.887  0.326  0.696  1.0
  O  O35  1  0.428  0.419  0.177  1.0
  O  O36  1  0.602  0.364  0.382  1.0
  O  O37  1  0.454  0.131  0.767  1.0
  O  O38  1  0.546  0.064  0.975  1.0
  O  O39  1  0.564  0.144  0.568  1.0
  O  O40  1  0.861  0.221  0.118  1.0
  O  O41  1  0.164  0.171  0.318  1.0
  O  O42  1  0.064  0.073  0.591  1.0
  O  O43  1  0.930  0.004  0.822  1.0
[/CIF]
.